Blindly install updated version each time. This morning downloaded updated version, had already read mail on Thunderbird then ran the new ccleaner version and done my HD backups. Went to mail again before work and was presented with a dictionary page for Thunderbird and the create an account. Mail blown away totally. Did my backups after the cleaner so those were shot as well. Was able to restore from Friday with another laptop, but lost some mail. Backed up and tested again. Ccleaner removed all again. Uninstalled the latest version and put the previous back. Will have to test the waters from here on out with each new version. Going to be a lot of unhappy Thunderbird users with this release.