Small white square on every map

Hey guys
I recently re-installed Garry’s Mod, but I noticed that around every map wherever I look there is a strange white square, it flickers if I look around. It’s rather annoying and gets in the way of screenshots and videos. Any ideas?

http://img580.imageshack.us/img580/827/hl22011080621504775.png

It is just on Soldier’s chest, you can’t miss it.
Any help would be appreciated guys. Thanks :slight_smile: