RENDERMODE_ON_DEMAND is broken on Firefox 3.5.3 in Vista32

[GoogleCodeExporter]

What steps will reproduce the problem?

1. Open render mode example page on Firefox 3.5.3 in Vista32:

   http://o3d.googlecode.com/svn/trunk/samples/render-mode.html

2. Click on RENDERMODE_ON_DEMAND radio button.

3. Open any other page in a second tab.

4. Go back to the first tab with render mode example.

What is the expected output? 

- You should see a rendered teapot.

What do you see instead?

- Instead the whole o3d viewport is filled with the content from the second
tab.

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

- Firefox 3.5.3 in Vista32

What hardware are you using:  graphics card type?  motherboard type?

- ATI Mobility Radeon HD 3650, Thinkpad T500

Please provide any additional information below.

- This bug started immediately after upgrading o3d plugin from version
0.1.40.1 to 0.1.42.2 

- It appears only in Firefox, Chrome and Explorer are fine.

- It happens also with my own code, so it seems it is not just a trouble
with the example. 

- It appears as if o3d plugin wouldn't get notified of viewport visibility
changes. It's not just tab switching, any other viewport cover/uncover
event (like move some window across viewport) does not result in redraw.

Original issue reported on code.google.com by uli...@gmail.com on 7 Oct 2009 at 8:08

[GoogleCodeExporter]

Similar behaviour which may be the same bug occurs when you scroll the page. If 
you
scroll rapidly then O3D flickers between the previous tab and the plugin 
content.
This only seems to be a problem in Firefox.

Original comment by did...@gmail.com on 14 Jan 2010 at 9:34

[GoogleCodeExporter]

Firefox in windows XP will also met the same issue.

Original comment by chihhaoy...@gmail.com on 23 Mar 2010 at 1:33