[Dovecot] possible bug with incoming mail

I've been using Dovecot for a couple months now and am very impressed. Thanks for a great package.

However, I have noticed a problem that I haven't been able to solve. When a new message comes into my inbox, the last message that was received is marked as new as well as the new one.

I originally thought this was a bug in my client (mutt) but I have verified that the same thing happens with Thunderbird, Sylpheed, mutt, and pine.

My configuration is as follows:

using mbox: default_mail_env = mbox:/var/spool/vfolders/%d/%n:INBOX=/var/spool/vmail/%d/%n

using imaps

Linux version 2.6.11-hardened-r1 (root@gondor) (gcc version 3.3.5 (Gentoo Linux 3.3.5-r1, ssp-3.3.2-3, pie-8.7.7.1)) #2 Thu May 5 13:14:52 EDT 2005

Thanks for any help you can give, Luke