Graphics are suddenly going crazy

[cali141]

http://smg.photobucket.com/albums/v4...enShot0003.jpg
http://smg.photobucket.com/albums/v4...enShot0000.jpg

As you can see (I can get more pics if you want), the textures on random things get all messed at random. When I say random, I mean it'll happen to the ground, equipped gun, HUD, map, etc... and sometimes after I respawn, its not there any more. Sometimes after I respawn, it suddenly pops up in other places. Whenever it does happen, it gives me a bunch of lag, which only makes the problem worse. What's going on? For a while, this never happened, then it just randomly started one day.