User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b7) Gecko/20100101 Firefox/4.0b7 Build Identifier: 4.0b7 The screen area paints to an incorrect size, and the scroll bars are often painted over. Occasionally (like maybe 2% of the paints) the window also gets scrambled. Reproducible: Always Steps to Reproduce: 1. Resize the window by dragging the bottom-right corner (or a side edge) Actual Results: I'll attach some screenshots. From about:support / Graphics... Adapter Description: NVIDIA GeForce GTX 260 Vendor ID: 10de Device ID: 05e2 Adapter RAM: 896 Adapter Drivers: nvd3dumx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um Driver Version: 8.17.11.9745 Driver Date: 4-3-2010 Direct2D Enabled: true DirectWrite Enabled: true GPU Accelerated Windows: 3/3 Direct3D 10 Note, not the latest driver. I thought I'd post this ticket first in case you want me to test anything out before I update.

Argh, sorry. Wrong component.

Steps to get the above screenshot: 1. Right-click on toolbar, Customize... 2. "Add New Toolbar", creating the new item "abc" 3. Right-click on the toolbar again Adding a second toolbar makes the menu render correctly again. Anyway, the reason I mention this is that it now looks to me like ticket 613102 could be the same issue. (Failing to reallocate the graphics buffer for the menu, or something.)

This is fixed for me in Nightly build 2010-Dec-22. I downloaded and tested after seeing Bug 613790 comment 26.