Weird CS 1.6 Problem

My friend has had counter strike for awhile now, but recently he has had a problem with getting "kicked" from servers. Every time he connects to one he can play for maybe 3min, or sometimes 3hours! But eventually he gets an error that says "Bad Data File" and he is removed from the server and taken to the main menu! It doesnt say "kicked" and that being the reason though. His game just stops and he is put to the menu with that Error! Someone please help!


Some of the things he has tried.
1. Reinstalled steam
2. Reinstalled Counter Strike
3. Reinstalled his GUI (the Cevo and tha CPL Pro)
4. He tried playing without a custom GUI (boring nad dull though)

Nothing seems to help, could someone please post some other things he could do. Or possibly someone else out there has ran into the same problem!

Turn off universal plug and play on the firewall appliance you are using.
Unload any peer to peer software you are using. If you have a software type firewall ie norton, dump it and get a real firewall appliance like a dlink or linksys or cisco
If he is playing on wireless, don't

also lower the keybard typematic rate.
if using a laptop and a bluetooth mouse, get a wired mouse.

Lots of answers, its a tough one. You can also put in a trouble ticket with valve software too.
Good luck. I have been playing CS since beta 1 in 99