When running Dovecot (rc6 CVS dovecot-20060808) as a proxy, why would it log the following when it has not yet maxed out the allowed number of imap-login processes?

Aug 10 16:23:34 director5 dovecot: imap-login: Disconnected: Connection queue full:

I am seeing this logged several times per minute. From netstat, the server has 650 proxied IMAP connections and 450 proxied IMAPS connections, there are currently 10 imap-login processes running, and using the following config:

login_process_per_connection = no login_processes_count = 3 login_max_processes_count = 20 login_max_connections = 225

I would think that under these conditions we should never see "Connection queue full" being logged.

Thanks, Bill