Garry's mod keep crashing when someone shoot in my face

System hardware specs
Processor: AMD Athlon™ X2 Dual-Core QL-64 2.10 GHz
RAM: 4,00 GB
Graphics Card: ATI Radeon HD 3200 Graphics
Operating System: Windows Vista 64-bit

I didn’t download anything but i activated client pass for Counter-Strike: Source. (It gave me all things to garry’s mod)

I can play normal in garry’s mod and use everything but when i have war with friends and someone stay close n straight to me and take even one shoot game freeze on 5-20 sec and then crash.

Help…

Right click the game on steam, click properties, launch options, Type in -dxlevel 81

Remove this after you start the game, or you will always go into 1024x768 or whatever.