I'm running Zimbra 5.0.0_RC1_1538.DEBIAN4.0 and have a problem with one account (mine!) where the unread count on Inbox is persistently 1 greater than the actual count. "Mark all as read" leaves the unread count at 1.
This is not an Ajax problem -- Squirrelmail running over the same imap service reports the same count.
Any suggestions gratefully received.