courier-tls Virtual Users And Domains With Postfix, Courier And MySQL (Debian Etch)

I've had this setup up and working great for months. I just noticed a lot of messages like this in my mail.log files

Oct 27 19:29:44 server imapd-ssl: couriertls: read: Connection reset by peer

I've searched around and can't figure out what they mean, how to get rid of them, or if they matter (seems like they do).

Mail seems to be flowing in and out fine.

What do these mean and how can I fix it?

As usual, thanks again.