The one that is number 1
How many times did you join the alliance?
Ok, as far as I can see you have joined, the database says you have. Did you log out and login again as stated?
Strange, it should be ok, the only difference you should see is in the alliance page saying your a member of an alliance etc.
I've got kind of the same problem, I joined ISG but the alliance ID (on the create-route-screen) is 0.