COD4 Connection Issues..

Can someone gimmi a hand please? every time i try to connect to a server it comes up with setting up game and then comes back to desktop saying Impure client detected. invalid .IWD files refrenced! …..modern warfare\main\iw_06.iwd
any replys would be great
Answer #1
f the problem is persistent im not really sure what can be wrong.
But i usually get that problem when the CoD 4 masterserver is slow or late at nights when there are thousands of players online.
I can usually connect to my own server withing a second or two after pressing connect, but as i say when the master server is slow it can take 5-10 seconds or even be connection timeout. And i also get the awaiting key code author from time to time.
If you got all ports open and everything set correct i assume its the master server issue that are slowing it down.

Edit:
PUNKBUSTER is most likely the problem, the game does not seem to want to auto update it which causes endless looping.
GO HERE http://www.evenbalance.com/index.php?page=pbsetup.php to update COD4 Punkbuster.
Answer #2
thanks for your response ill give it a go