When I signed up for a new twitter account and followed a few sources, I didn't have anyone following me. When I selected "Followers" I would get an error and the busydialog would not close.
To fix, in gui.py, 'def getFollowing(self)' should have the lines from self.api.GetFriends() to the end of the for loop wrapped with a try/except block. That way, even with an exception the xbmc.exececutebuiltin("Dialog.Close(busydialog)") gets called.
(A similar problem and similar solution is with getFollowers() and getDirectMessages())