[Dovecot] IMAP server <defunct> (beta 7)

[Graham Briggs]

Hi,

We've been using a 0.99 version of Dovecot for nearly a year without  
problems, but due to a server death I had to reinstall with the same  
configuration as before, but more recent versions of the software, on  
different hardware.

This time though, every few days IMAP login and access fails, and the  
output of ps ax shows entries such as [imap-login] <defunct> and  
[imap] <defunct>, with the lovely brain-eating Zombie status. There  
is nothing in the log file that suggests an issue.

We're using dovecot with authentication/etc being done against a  
Postgresql database. I searched online for a solution, but the  
nearest problem said it was a problem with PAM, which we are not  
using with Dovecot. We're using Maildir as the message storage format.

Does anyone have any suggestions as to why this might be occurring?  
If it will help to see the dovecot configuration files then I can  
provide them.

The platform is Debian 64-bit running on a dual-core Opteron system.  
Yes, it isn't Debian-stable!

Graham