vidalia should getinfo status/bootstrap-phase upon connecting to the control port
Vidalia currently connects to the Tor control port, authenticates, and waits for bootstrapping events. When it gets an event, it moves the bootstrap status bar forward.
But if Tor already has the directory info cached, then those events will get sent before Vidalia finishes authenticating. So Vidalia will miss them and it will wait for Tor to finish building a circuit but the bootstrap bar still says it's "authenticating to Tor".
Worse, if Tor somehow finishes bootstrapping before Vidalia finishes authenticating, Vidalia will never hear a bootstrap event, and it will never move to a green onion.
The fix is that Vidalia should do a 'getinfo status/bootstrap-phase' when it connects, and pretend it just got that event.