Technically, TB didn't actually lose the messages. It just scattered them to the four winds, where they would never be found. It moved them out of Local Folders, back into the mail box accounts where they came from. There they were archived by year in various folders. I managed to restore them back into Local Folders from a backup. Incidentally, that procedure was not without white knuckles because I had added a subfolder since the backup, and TB just went berserk. This is not for the faint of heart. I can attest that things can go very wrong. Be sure to back up the profile before you try this, and don't make any changes to the profile while TB is open.