Halo multiplayer problems?

I have Halo Comat Evolved. Campaign works just fine and so does everything else EXCEPT for multiplayer. Whenever I try refreshing the multiplayer menu, several seconds later an error message pops up saying that an error has occured connecting to the Gamespy Master Server. I don't know why. All my firewalls are apparently configured to allow Halo and Gamespy, so I don't know what's wrong. Someone please help!

maybe the gamespy server is having problems