radeon 4670 graphics bug

[:1]did not find similar bug posted.
after i go alt-tab to windows and back in the game, some textures go black, probably shaders or illumination go down as well
|||win7 x64, catalyst 10.3|||don't alt tap if your having trouble|||Or play in windowed mode.|||workarounds...
well, not like i'm having trouble with it, just reporting a bug.
not my vcard anyway, gonna switch back to 9800gt in a couple of days