Disappearing Weapons

Everytime I look at an NPC this happens:

http://img825.imageshack.us/img825/4295/hl22010091413471968.png

But everytime I look away:

http://img826.imageshack.us/img826/3742/hl22010091413472282.png

Help?

Anyone?

try r_lod 0 in console