To make sure we understand your problem clearly, can you please confirm that you saying you can play the game normally when you go into the game with your Facebook account, but you when you try to log into another account from the settings menu, you get stuck?
Can you mean sure you are access the game using the URL below, without any things after it (make sure there is no parameters like "?minad=...." after it. If so, please remove everything after the "?" or just only use the following url)
https://apps.facebook.com/dragontear/