Need help on connectiong to MP games...

Ok I have no idea why but the other night I tried to log onto a custom game and I see people in lobby and games they have created but when I try to connect it just sits there and nothing happens. fist time was a crash where it locked up second time it took a long time and I just cancelled. Any ideas what I need to do? I have a Linksys router hooked up. Thanks...

P.S. The first time after I went back to the screen it said Iw as kicked by the host but I never entered the game... Please explain...