check to see what your ingame fps is and then do a

/console maxfps #

where # is about 5 fps lower then the fps you're getting.




imo something screwed up with the last patch with some videocards that run the game at max potential, slightly lowering it down might remove the glitches (if this is the problem you have).

The other thing is a busted videocard or memory or motherboard or ugh, could be many things. But try this first and memory tests.