issues with new gnus nnimap

[joakim]

Ok, I would have liked to not discgrace myself with a really low quality
problem report, but here goes anyway:

I have used the old gnus nnimap for a long time with a local dovecot
server on my laptop. This has worked ok, except that gnus never counted
the number of messages in the folders correctly. I could work around
this with M-g on imap folders I knew gnus normaly failed to do the
calculation in.

Noticing the enourmous code churn in gnus, I tried a new Emacs snapshot
the other day. I then got different behaviour. Old emails from 2006
showed up as new ones. I tried to do catch up on them. They seemed gone,
and then I did M-g on the group, and they came back again.

Then I got too scared to continue, and reverted to my old Emacs.

Any hints how to provide better debugging info apreciated.

-- 
Joakim Verona