Garry's mod crashes on every multiplayer game

Please read the EDIT notice at bottom of the post.

Hello.
I have got a big problem with my Garry’s mod. Whenever I join multiplayer game, the game crashes immediatelly after joining. It shows me the map for a tiny moment (less than 1 sec). Then it stucks, minimalizes and I get my “favourite” message that HL2.exe stopped working and needs to be closed. There is no dump file created in Steam/dumps folder. I have already tried:

• to get fresh copy of Garry’s mod by renaming steamapps/mysteamusername/garrysmod to garrysmodx
• to run Steam as administrator
• verify game cache
• truncate the cache folder
• start singleplayer game before joining multiplayer game --> I have managed to attempt to debug the HL2.exe what stopped working with my Visual Studio:



Unhandled exception at 0x0080047f in hl2.exe: 0xC0000005: Access violation.
Clicking "continue" button didn't make any sense, the exception was called again and again (obviously.. :D)

Call stack:

01# 0080047f()
02# MaterialSystem.dll!6ecbf8fe()
03# [Frames below may be incorrect and/or missing, no symbols loaded for MaterialSystem.dll]
04# MaterialSystem.dll!6ecbe51c()
05# MaterialSystem.dll!6ecbec0f()
06# MaterialSystem.dll!6ecbfc12()
07# MaterialSystem.dll!6ecad283()
08# MaterialSystem.dll!6ecada21()
09# MaterialSystem.dll!6ecad7ea()
10# vstdlib.dll!6ee33f74()
11# vstdlib.dll!6ee36479()
12# tier0.dll!6ee9a83d()
13# tier0.dll!6eea8771()
14# tier0.dll!6eea8816()
15# kernel32.dll!76713677()
16# ntdll.dll!77249f02()
17# ntdll.dll!77249ed5()



I played 500 hours of Garry’s mod on this computer and never had this problem before. An only thing I made was that I have updated the graphics card driver. It was about 150 revisions old (lol).

Specifications:
Graphics card - NVIDIA GT 220M (newest driver)
Processor - Intel® Core 2 Duo - each core @2,2 GHz
RAM - 4 GB
Operation system - Windows 7 Home Premium 64bit version

EDIT! Garrys mod doesnt crash on every mp game. It looks to be server specific. Is that possible? How to fix it then? Server: http://forum.urbangamers.org/index.php - IP: 79.161.132.134:27015

I will appreciate any help from you.

Thank you very much.

Khubajsn