Gmod "crashes" but can still hear sound

[RonanZer0]

OS: Windows 7 x64
CPU: Intel i5 2500k
GPU: AMD Radeon HD 7950
RAM: 4GB

Issue: Sometimes, when playing GMod, while experiencing high FPS and no lag or anything like that, GMod will minimize OR go to a black screen. Then, I can still hear everything that goes on, heck I can even type stuff in the console and it works, but I can't actually [i]see anything[/i]. And in the case of it minimizing, GMod is just a small black bar at the top left of the screen.

The only thing going on is a small 6 player deathmatch.

EDIT: "Display driver AMD has stopped responding" when it does that.

EDIT2: It looks like this while playing:
[t]http://i.imgur.com/8lST4Do.png[/t]

[RonanZer0]

[QUOTE=~Kiwi~v2;47760859]Updated Graphics drivers?
Not running any other applications?
Checked background applications and seeing if they want attention?[/QUOTE]
Only things open were Chrome, Steam, and task manager... nothing else.

[RonanZer0]

Also now it's constantly crashing my entire PC with a grey screen! Even while doing nothing on it.