User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/532.5 (KHTML, like Gecko) Chrome/4.0.249.11 Safari/532.5 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.5) Gecko/20091121 Thunderbird/3.0 I chose the smart folder option in the migration assistant when I upgraded from Thunderbird 2.x instead of continuing to use separate inboxes. If I'm in the new smart inbox, selecting mark all as read or using the associated shortcut does not work. It only works if I go to one of the individual account subfolders under inbox. Reproducible: Always Steps to Reproduce: 1.Use smart folders with multiple accounts 2.Wait for a number of messages to arrive across various accounts 3.Go to global inbox smart folder 4.Go to Message->Mark->All Read Actual Results: Nothing Expected Results: Should have marked all messages in the inbox as read.

Does it happen in safe-mode too (http://kb.mozillazine.org/Safe_mode) ? Anything in tools->Error console when this happens ?

Yes it does happen in safe mode and there are no errors reported in the console.

Ugh, it would have been nice if that came up in bugzilla's search. I searched for mark all read and found nothing useful.