unable to join servers

[guchi]

i tried to join a server, but a steam window popped up, saying join and refresh and stuff (the one you get when the server is full, but without the auto refresh, and without the being full-ness) so i pressed "join" and it started loading, but when it reached 3 loading bars it went back to the server browser... i tried different servers, and the exact same thing happened, i even tried servers that i had gone to yesterday... didnt work...

any help?