swfobject 2.1,div contain flash cannot cover other divs

What steps will reproduce the problem?
2 divs, both has same width height, the first div has background image,
second contains flash,and use margin-top:-150px or position:absolute to
make second div cover the first one. (please see the code below)

What is the expected output? What do you see instead?
1.5 or previous version 2 div are overlapping, but in 2.1 version the
second div always hold its own position, i need the first div's background
image,and also when flash is onloading, the page can show something,not
just empty

What version of the product are you using? On what operating system?
version2.1 has this problem, 1.5 or previous version work well.

Please provide any additional information below.

code:
<script src="swfobject.js"></script>

<div style="width:200px;height:200px;background:green;"></div>
<div id="test"  style="margin-top:-150px; width:200px;height:200px"></div>

<script>
swfobject.embedSWF("adtop_cn.swf", "test", "200", "200", "6.0.0",false);
</script>

Original issue reported on code.google.com by warcraft...@gmail.com on 3 Apr 2009 at 2:59

thuansaritasa / swfobject

swfobject 2.1,div contain flash cannot cover other divs #294