Need more information. The game has been out for a while, so did you just get the game and have you had problems the whole time? I assume you have it patched? Computer specs? Do you have Crysis?
I'm trying to remember... I had a similar problem, and I think it only happened with Warhead. It was with setting r_TexturesStreaming to one. My CCC config that I used for Crysis did that for some higher details or performance. Or maybe the problems were with setting it to zero. I can't remember but you might want to look into it. I'm looking at my Crysis autoexec.cfg and I am setting it to one. In my Crysis Warhead autoexec.cfg, I commented out that line.