You have to wait for the response from the server before you can join the created room. SFS is a response/request system, so if you fire off commands right after each other, then its not guaranteed that the server has had time to create the room for you yet.
You can check out the tic-tac-toe tutorial code, where I create a game room that is then joined. But basically wait for the joinroom until server has responded that the room has been created.
I'm having a similar problem. I understand the need to first create a room, and then attach the joinRoom to the rommlist update event. (once the server responds) However, when i use this code to create a room (straight from the sfsTris example) i don't get a roomCreateError, or a roomListUpdate. It just hangs.