You probably already done this but please check that all your extensions are up-to-date. I upgrade to TB5 overnight and most of my extensions said they were compatible but were not. I was getting the No Domains errors for most of my accounts too. There was no related error message in the Error Console that I could find.
Current TB5 Versions that are working for me are as follows: AOL 1.30.a1 Gmail 0.7.0 Hotmail 1.3.3 Yahoo 1.5.0 Webmail 1.4.1 Eugene
