This bug happens in both windowed mode and fullscreen mode but it was easier to get a screenshot from a window. I'm running the Steam version and I've tried verifying the game cache as well as deleting the game and reinstalling. I've tried running the demo game and the same glitch happens there too. I've also run the DirectX installer to make sure I have the latest components installed and it hasn't helped. Neither has reinstalling my video drivers and rebooting.
Windows Vista SP2 64-bit
Core2Duo E8400 3.0GHz
6 GB
ATI Radeon HD 4850 512MB
Driver versions:
Catalyst 9.9
Driver Packaging Version 8.65-090813a-087739C-ATI
2D Driver Version 8.01.01.949
Direct3D Version 8.14.10.0697
OpenGL Version 6.14.10.8918
DxDiag reports



Set that to standard instead of advanced. 
