imapd 100% after viewing a few messages

[warren at netlab.co.za]

Greetings

I have been setting up a new cyrus-postfix-amavis(new)-spamassassin system and 
have come across a problem. Cyrus master starts without problems. I can send 
messages and I can usually view the message. But for some reason, after viewing 
a few messages the imapd process starts using 100% of CPU.

Unfortunately there is very little other info that I can send. The imapd.log 
shows nothing unusual. The only entry that resembles a problem is

Nov 24 15:09:13 xserverii imapd[10410]: SQUAT failed to open index file
Nov 24 15:09:13 xserverii imapd[10410]: SQUAT failed

but after a google or two it seems that this is normal.

Messages logs shows nothing unusual. Neither does maillog or auth.log.

I can always reproduce the problem by using squirrel mail (outlook also shows 
shows the same problem so it is not a client problem) by going though the first 
6 emails. Before the end of the list the problem presents itself (sometimes on 
message one, but usually I can view a few before the problem starts).

All software (cyrus/postfix) are the latest stables as of a few weeks ago. The 
system is RH8.0.

I have tried to use gdb in an attempt to offer something more in this request 
but have been unable to obtain any useful info (this is the first time I have 
attempted used gdb seriously, so its mostly my ignorance that is the problem).

Any ideas of how to track this problem down would be most welcome.

Regards
Warren