invalide height of mathlformula compoment

What steps will reproduce the problem?
I juste put this mathml formula :

<math>
        <mrow>
                <mrow>
                        <msub>
                                <mi>x</mi>
                                <mtext>12</mtext>
                        </msub>
                        <mo>=</mo>
                        <mfrac linethickness="1">
                                <mrow>
                                        <mo>-</mo>
                                        <mi>b</mi>
                                        <mo>&plusmn;</mo>
                                        <msqrt linethickness="1">
                                                <msup>
                                                        <mrow>
                                                                <mi>b</mi>
                                                                <mrow mathvariant="italic">
                                                                        <msub>
                                                                                <mi>x</mi>
                                                                                <mtext>12</mtext>
                                                                        </msub>
                                                                        <mo>=</mo>
                                                                        <mfrac linethickness="1">
                                                                                <mrow>
                                                                                        <mo>-</mo>
                                                                                        <mi>b</mi>
                                                                                        <mrow>
                                                                                                <msub>
                                                                                                        <mi>x</mi>
                                                                                                        <mtext>12</mtext>
                                                                                                </msub>
                                                                                                <mo>=</mo>
                                                                                                <mfrac linethickness="1">
                                                                                                        <mrow>
                                                                                                                <mo>-</mo>
                                                                                                                <mi>b</mi>
                                                                                                                <mo>&plusmn;</mo>
                                                                                                                <msqrt linethickness="1">
                                                                                                                        <msup>
                                                                                                                                <mrow>
                                                                                                                                        <mi>b</mi>
                                                                                                                                        <mrow>
                                                                                                                                                <msub>
                                                                                                                                                        <mi>x</mi>
                                                                                                                                                        <mtext>12</mtext>
                                                                                                                                                </msub>
                                                                                                                                                <mo>=</mo>
                                                                                                                                                <mfrac linethickness="1">
                                                                                                                                                        <mrow>
                                                                                                                                                                <mo>-</mo>
                                                                                                                                                                <mi>b</mi>
                                                                                                                                                                <mrow selected="true">
                                                                                                                                                                        <msub>
                                                                                                                                                                                <mi>x</mi>
                                                                                                                                                                                <mtext>12</mtext>
                                                                                                                                                                        </msub>
                                                                                                                                                                        <mo>=</mo>
                                                                                                                                                                        <mfrac linethickness="1">
                                                                                                                                                                                <mrow>
                                                                                                                                                                                        <mo>-</mo>
                                                                                                                                                                                        <mi>b</mi>
                                                                                                                                                                                        <mo>&plusmn;</mo>
                                                                                                                                                                                        <msqrt linethickness="1">
                                                                                                                                                                                                <msup>
                                                                                                                                                                                                        <mi>b</mi>
                                                                                                                                                                                                        <mn>2</mn>
                                                                                                                                                                                                </msup>
                                                                                                                                                                                                <mo>-</mo>
                                                                                                                                                                                                <mn>4</mn>
                                                                                                                                                                                                <mi>a</mi>
                                                                                                                                                                                                <mi>c</mi>
                                                                                                                                                                                        </msqrt>
                                                                                                                                                                                </mrow>
                                                                                                                                                                                <mrow>
                                                                                                                                                                                        <mn>2</mn>
                                                                                                                                                                                        <mi>a</mi>
                                                                                                                                                                                </mrow>
                                                                                                                                                                        </mfrac>
                                                                                                                                                                </mrow>
                                                                                                                                                                <mo>&plusmn;</mo>
                                                                                                                                                                <msqrt linethickness="1">
                                                                                                                                                                        <msup>
                                                                                                                                                                                <mi>b</mi>
                                                                                                                                                                                <mn>2</mn>
                                                                                                                                                                        </msup>
                                                                                                                                                                        <mo>-</mo>
                                                                                                                                                                        <mn>4</mn>
                                                                                                                                                                        <mi>a</mi>
                                                                                                                                                                        <mi>c</mi>
                                                                                                                                                                </msqrt>
                                                                                                                                                        </mrow>
                                                                                                                                                        <mrow>
                                                                                                                                                                <mn>2</mn>
                                                                                                                                                                <mi>a</mi>
                                                                                                                                                        </mrow>
                                                                                                                                                </mfrac>
                                                                                                                                        </mrow>
                                                                                                                                </mrow>
                                                                                                                                <mn>2</mn>
                                                                                                                        </msup>
                                                                                                                        <mo>-</mo>
                                                                                                                        <mn>4</mn>
                                                                                                                        <mi>a</mi>
                                                                                                                        <mi>c</mi>
                                                                                                                </msqrt>
                                                                                                        </mrow>
                                                                                                        <mrow>
                                                                                                                <mn>2</mn>
                                                                                                                <mi>a</mi>
                                                                                                        </mrow>
                                                                                                </mfrac>
                                                                                        </mrow>
                                                                                        <mo>&plusmn;</mo>
                                                                                        <msqrt linethickness="1">
                                                                                                <msup>
                                                                                                        <mi>b</mi>
                                                                                                        <mn>2</mn>
                                                                                                </msup>
                                                                                                <mo>-</mo>
                                                                                                <mn>4</mn>
                                                                                                <mi>a</mi>
                                                                                                <mi>c</mi>
                                                                                        </msqrt>
                                                                                </mrow>
                                                                                <mrow>
                                                                                        <mn>2</mn>
                                                                                        <mi>a</mi>
                                                                                </mrow>
                                                                        </mfrac>
                                                                </mrow>
                                                        </mrow>
                                                        <mn>2</mn>
                                                </msup>
                                                <mo>-</mo>
                                                <mn>4</mn>
                                                <mi>a</mi>
                                                <mi>c</mi>
                                        </msqrt>
                                </mrow>
                                <mrow>
                                        <mn>2</mn>
                                        <mi>a</mi>
                                </mrow>
                        </mfrac>
                </mrow>
        </mrow>
</math>

What is the expected output? What do you see instead?

And I see , that the mathmlformula's height is smaller than the display area so 
if overlay the other compoment in the interface

What version of the product are you using? On what operating system?

FLEX MATHMLFORMULA 1.1
Original issue reported on code.google.com by tantuan....@gmail.com on 12 Aug 2010 at 8:18
ianharrigan / mathmlformula

invalide height of mathlformula compoment #22
