Yep, I'd turned on imap/pop3 proxy and those commands are what I did to work around the problem. Trouble is, the problem will come back when the server is rebooted so I need to do that every time unless there's some more permanent way to turn them off.
Thanks for the "how to get the version" tip, the answer is-
Release 4.5.5_GA_838.SuSE10_20070503170511 openSUSE_10.2 FOSS edition
Man, pity you can't do imap/pop3 on a single server.