cant join the game server?

Hello

I have used the iw4m client to play mw2 but every time i connect to the game server it stuck at ( setting up the game ) and i go to the console and the stuck at ( [NP] Sending RPC message with ID 0.) and he resend this command four time then he said ( server connection time out ) so i cant play in any server and i reinstall the game and the client but the same problem and when i use alter m1 ( before it hack ) the game work fine.