lost mailbox lock

[urgrue <urgrue tumsan fi>]

if i leave a mailbox untouched for even a little while (a minute or 
two), the next time i try to do anything i get an error:
Lost mailbox lock
Connection to <mail server> closed
Mailbox closed
CLOSE failed

Most annoying thing is, all my message tags (deleted, read, etc) are 
forgotten. 
I presume this isnt really a balsa problem, but at least i dont get it 
with Eudora, for example.

I've even set "Automatically close mailbox if unused" and 
"Automatically commit mailbox is unused" both to 1 minute, and it 
doesnt seem to help.

This has happened to me with every balsa version i ever used (since 
1.0.x until now, at 2.0.11)

I figure this is some idle timeout thing on my imap server, which is WU 
imap, which has also been upgraded many times. currently its the latest 
stable version.

any ideas how to fix it?

(according to the man page, wu-imap's timeout default value is 30 
MINUTES)