Problems with Call Of Duty 4 multiplayer

[Griever14206]

I have been playing Call of Duty 4 Single player for a few days now and when i tried to play multiplayer using the shortcut on my desktop the game starts but then immeadiatley crashes to desktop. I get the follow error:

Problem signature:
Problem Event Name: APPCRASH
Application Name: iw3mp.exe
Application Version: 0.0.0.0
Application Timestamp: 47043f08
Fault Module Name: iw3mp.exe
Fault Module Version: 0.0.0.0
Fault Module Timestamp: 47043f08
Exception Code: c0000005
Exception Offset: 00276555
OS Version: 6.0.6000.2.0.0.768.3
Locale ID: 1033
Additional Information 1: 8d13
Additional Information 2: cdca9b1d21d12b77d84f02df48e34311
Additional Information 3: 8d13
Additional Information 4: cdca9b1d21d12b77d84f02df48e34311

I'm thinking about reinstalling the game but I'm interested as to why it simply will not work, any suggestions?

[smurfy]

Have you patched to 1.5?