User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; de-DE; rv:1.9.2) Gecko/20100115 Firefox/3.6 Build Identifier: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.1.8) Gecko/20100216 Thunderbird/3.0.2 After the Update from TB 3.0.1 to 3.0.2 the prefs.js is manipulated in that way that some (not all) IMAP-Accounts were lost and not shown after a restart of TB. If I replace the prefs.js with a backedup version the IMAP-Accounts were shown by the first start but again removed by quitting and restarting TB. This is reproducable. The onlny workaround that works is to set a write protection on the file prefs.js. Reproducible: Always

We've just fixed one problem with accounts, I doubt it will solve your issue, but please could you try a build from: http://ftp.mozilla.org/pub/mozilla.org/thunderbird/nightly/latest-comm-1.9.1/ and see if you get the same issue. If that doesn't work, would you mind sharing with us your mail.* preferences so that we can debug the issue?

Joseph, the latest comm 1.9.1 build should prevent the issue from happening again, as long as it was built after 2/26 5PM PST, once you use your backed up prefs.js. It won't repair the bad prefs.js, however. This is a dup of Bug 548735. Unlike the local folders case in bug 548735, we can't really know that this corruption has happened, unfortunately. There will be some stray account and server prefs in prefs.js, not hooked up to the accountmanager.accounts list of accounts, but we don't know if those were left there from previously removed accounts, or caused by this bug.

Hi Mark and David, thank you for your both fast reactions. You're right with the build Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.1.8) Gecko/20100227 Shredder/3.0.3pre it works again. Thanx! :)

Joseph Doer, do you have backups of prefs.js? - prefs.js before use by Tb 3.0.2 - prefs.js after use by Tb 3.0.2 (IMAP account is lost) If yes, can you present next entries in backups to us? > mail.accountmanager.xxx = account1,account2,account3,account4 > mail.account.accountN.server > mail.account.accountN.identities > mail.accountmanager.localfoldersserver = server1 > mail.server.servrX.xxx If it's hard to open to public(for security reason, ...), can you send backups of prefs.js to David via mail?

I don't really need backups of prefs.js at this point, actually.