On Mac OS X 10.7.5 running latest version of Thunderbird (though it started with the version I had previously installed) Thunderbird freezes shortly after starting application. It goes through the rounds of trying to get messages and asking me for passwords, then hangs there and won't let me do anything. I have tried starting in Safe Mode (holding Shift while starting up) but it doesn't seem to start up in Safe Mode, and has no effect. Can't get into Help menu to try to restart with add-ons disabled. Have tried to look at Crash Reports, but don't think it is generating any since usually I force quit.

Any help is greatly appreciated!