Rakion
 

I can't seem to join any games. I can connect to the server, but when I try to join a game, I always get this message.

"Your connection speed with one of the user in the room you chose to enter is very slow. Please use another game".

The problem might be with my router. But I've never had any problems with it, like playing WoW, Battlefield 2, or Frozen Throne. Suggestions?

It just means your connection speed is too slow to join that game, If would join it it would cause too much lag for you and other players so they don't allow you to join. I always just made my own room when I played.