It doesn't show in all folders, but sometimes Mozilla doesn't update folder status and still shows there are unread messages in particular folder. that means folder is written in bold, with number of unread messages (and shown also in bottom status bar). Looks as it happens, if you move to folder with unread messages and first unread message highlights. Status of message becomes 'read', yet folder still shows unread message. Workaround for losing ghost unread messages is to delete folder's summary file (<folder>.msf) and letting mozilla rebuld it.

Uh, forgot version. It happens with build id 2000111420, but i've seen it in previus versions, too.

*** Bug 60558 has been marked as a duplicate of this bug. ***

Possible dup of bug 32369?

yes, it is most certainly a dup of 32369 (did a cross checking). sorry for posting:) *** This bug has been marked as a duplicate of 32369 ***

Verified dupe.