it looks like a decompressing problem. have u tried to decompress all ur pk files or w/e into the base directory, so that u dont hafta decompress all the gfx during the game. But this should only make transitions smoother. Try tweaking the cache size, and there are some other things u can tweak, just google it. But u shouldnt be getting problems tho.. This is real wierd. i run doom3 on my setup, on high, in 1024, and im at 40 fps, smooth and all (i tweak a bit of course, hehe)