Big problem with Cyrus

[Karjala]

I have been running Cyrus with Exim on Debian for years now without any 
problems.

The past few days though, I've been experiencing this:

Once or twice a day, a process called ctl_deliver appears when I type 
"top", it consumes 50% of CPU time and doesn't stop running (I need to 
kill it to stop).

This process quickly fills in my hard disk's free space by appending to 
/var/log/mail.log and /var/log/syslog lines like the following, at a 
rate of 1MB per minute:

Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: starting txn 
2148261614
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: aborting txn 
2148261614
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: DBERROR: mydelete: error 
deleting 6f65b$ff9: DB_NOTFOUND: No matching key/data pair found
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: starting txn 
2148261615
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: aborting txn 
2148261615
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: DBERROR: mydelete: error 
deleting 6f65b$ff9: DB_NOTFOUND: No matching key/data pair found
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: starting txn 
2148261616
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: aborting txn 
2148261616
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: DBERROR: mydelete: error 
deleting 6f65b$ff9: DB_NOTFOUND: No matching key/data pair found
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: starting txn 
2148261617
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: aborting txn 
2148261617
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: DBERROR: mydelete: error 
deleting 6f65b$ff9: DB_NOTFOUND: No matching key/data pair found
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: starting txn 
2148261618
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: aborting txn 
2148261618
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: DBERROR: mydelete: error 
deleting 6f65b$ff9: DB_NOTFOUND: No matching key/data pair found
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: starting txn 
2148261619
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: aborting txn 
2148261619
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: DBERROR: mydelete: error 
deleting 6f65b$ff9: DB_NOTFOUND: No matching key/data pair found
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: starting txn 
2148261620
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: aborting txn 
2148261620
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: DBERROR: mydelete: error 
deleting 6f65b$ff9: DB_NOTFOUND: No matching key/data pair found
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: starting txn 
2148261621
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: aborting txn 
2148261621
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: DBERROR: mydelete: error 
deleting 6f65b$ff9: DB_NOTFOUND: No matching key/data pair found
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: starting txn 
2148261622
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: mydelete: aborting txn 
2148261622
Oct 28 04:27:58 h1 cyrus/ctl_deliver[22550]: DBERROR: mydelete: error 
deleting 6f65b$ff9: DB_NOTFOUND: No matching key/data pair found

And then everything stops working (because the HD is full), until I wake 
up and delete the log files and kill the process.

Running "ps" shows that ctl_deliver is running with the parameter "-E 3".

What could be the problem here?

How do I solve it?

Thx,

- Karjala