In-game f-up

Starting the game goes without any errors, but when I "press any button to start", this is all I see:
http://img59.imageshack.us/img59/4865/effedmap1.png
mostly the map look like this, but sometimes there are visible places like the one below.
http://img153.imageshack.us/img153/5237/effedmap2.png

I've downloaded and installed this mod twice, and updated to the latest patch, but I can't seem to figure out why this is happening :(

hmm my guess it something has gone tits up with your video card/drivers

Try updating your video drivers

I remember seeing something like this ages ago when we first added the PPSH, but that was a model problem. Since nobody else seems to have this, we could probably boil it down to a GFX card or driver issue.

I got a ATI Mobility Radeon HD 4650, which driver I've updated four times now, but it still won't work :(

Have you tried updating your DirectX?
What happens, when you lower the graphic settings?