Thunderbird error in both Vista and Leopard - SSL protocol disabled

When I was synchronizing my thunderbird mail folder between Mac Leopard and Vista, I accidentally pressed the stop button when the progress was half-way through. When I restarted Thunderbird, I was getting an error saying that "Thunderbird is not able to connect to the Imap….server because the SSL protocol is disabled" (in both Leopard and Vista). I searched Google but no luck. I then tried replacing the content of the Thunderbird profile folder with that of the backup I made for the same folder some time back. I replaced everything except the “Chrome”, “Mail” and “ImapMail” folders. Thunderbird was behaving normal again when restarted. I am glad I have learned to maintain a habit of making frequent backups. However, I think, in this case one could have also fixed the problem without the help of backups. Simply, install Thunderbird again in another directory of Windows, copy all the files, except for the above three folders and use them to replace those in the original Thunderbird profiles directory.