Graphic glitches in late game

[rcrindler]

I'm having some graphics issues with BTS. Everything starts off fine but latter in the game graphical glitches start appearing, including large black polygons covering the screen, cities and terrain improvements disappearing, and leader screens going blank. Eventually this can result in the game crashing. I got an error message mentioning something about my graphics card, but I have the latest drivers installed and my computer says its working.Is there anything else to do? Any help would be greatly appreciated.