I have a Debian Etch machine running Cyrus 2.2. We use it to access our mail through secure IMAP with Postfix as the MTA. Ever since we installed it it's run fine except for an annoying glitch. When browsing our IMAP folders with Thunderbird, sometimes all the messages in a folder will become unread. It appears to happen randomly and I can't for the life of me figure out why it's happening.
The permissions on the .seen files appear to be normal:
-rw------- 1 cyrus mail 4516 2007-01-02 20:29 /var/lib/cyrus/user/m/mike.seen
We don't have trouble using Thunderbird with a host of other IMAP accounts, so I'm pretty sure it's not the mail client.
I would appreciate if anyone could offer some hints or a solution. I haven't heard of this problem happening before (although I have heard cases where messages consistently come up as unread, due to problems with .seen file permission, but I'm pretty sure that's not the case here).
Thanks for any help!