It's not a terribly good screenshot, but it shows how this stuff starts. Click to enlarge:
I'll have to convert the video I took, it shows it a bit better. It starts with the minimap, then the text starts jumping around on the screen and changing sizes. When I finally get shot/wounded, shards of red kind of radiate from the center of the screen randomly.
When this happens, my framerates gradually get worse and worse. If the map changes, it doesn't go away, it keeps up with the wierdness even in the main menu. I have to restart the game to get rid of it.
Computer is a Dell E510 with a Pentium 3 Ghz, 2.5 gigs of RAM and an ATI X600 video card.