User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b6pre) Gecko/20100910 Firefox/4.0b6pre Build Identifier: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b6pre) Gecko/20100910 Firefox/4.0b6pre See STR Reproducible: Always Steps to Reproduce: 1. Open Firefox 2. Open Add-ons Manager 3. Enable any personas 4. Switch back to default theme 5. You will see that the Title and Tab bars appear black in colour if you enable Firefox Button. OR 5. You will see that the Menu and Tab bars appear black in colour if you enable the menu bar. 6. Resize Firefox and the problem is "solved" as they return back to their original glass theme colour.

Mozilla/5.0 (Windows NT 6.1; rv:2.0b6pre) Gecko/20100913 Firefox/4.0b6pre Works for me. Please check if you are still able to reproduce by creating a new profile. http://support.mozilla.com/en-US/kb/Basic+Troubleshooting#Make_a_new_profile and check.

This is a known problem with d3d9 layers

So do I still need to try if I can reproduce this in a new profile?

(In reply to comment #3) > So do I still need to try if I can reproduce this in a new profile? It would be nice if we can be sure this is fixed :)

Problem appears to be unreproducible but upon changing of theme from default theme to persona a temporary black bar still appear for a while before the personas appears.

Problem appears to be unreproducible but upon changing of theme from default theme to persona a temporary black bar still appear for a while before the personas appears. Moreover this also happens if you change from 1 personas to another.

The black is probably from the image loading. We can always report that as another bug; this one seems to be WFM.