Problem with GMOD graphics. Help me :C

When i’m on GMOD, i can see lines thought models and when i move down, they dissapper. I move up, the sky glitches up.

GMOD used to work well before… now it’s glitching up even in low quality…
and weird, i can run TF2 Fullscreen Almost Medium Quality without glitching up (well rarely).

Any help?

Specs:
AMD PHENOM X4 9550 QUAD-CORE
Geforce FX 5200. (ITS A OLD CARD, I KNOW, BUT IT USED TO WORK WITH GMOD VERY WELL)
Windows 7 32-Bit (It was windows vista before but, changed to 7)
6 Go of system memory
185 go of free HD space.

Screenshots : http://imgur.com/aCsh8,MtzRP

[editline]6th December 2012[/editline]

No help? I’ll wait.

Have you tried updating your video card drivers?