On the 1on1 ladder I've just been challenged by a new player who wanted to "get a feel for the game". I told him it would be more sensible to practice 1on1 before starting a match but he wouldn't listen. So I connected to delight and waited ... and waited ... and explained him twice how to join the game, but according to him he "saw" me but couldn't enter the match ...
Eventually I found out that he was clicking on the server name in the ladder server list because he'd mistaken Nexuiz for a browser game

I've just suggested he'd better play a while on the public servers before challenging anyone ...
Happy fragging,
MM