Playermodel head missing

Heya, hope someone can help me out! :S
I recently went on a friends server and noticed my playermodel had no head, I thought it was just a bug on the server, but now whenever I play single player my playermodel, no matter which one I change to, is without a head!
Anyone who can help me, thanks in advance!

Screenshots ?
Maybe one of your addons is conflicting with playermodels ?

the first image is viewed through a camera, the second is third person, so, the “headless” effect is only visible through the player camera.

Weird right?

[editline]13th May 2012[/editline]

I’ve linked an Imgur with screenshots, hope they help!