[Dovecot] dovecot newbie question about "invalid key" problem

[Joakim Verona]

Hello list,

I've trying to migrate a small uw-imap server to dovecot.

It works somewhat, and speed seems greatly improved, so thats great.

However, I get an "invalid key/Internal Error" problem when connectiong 
to my INBOX
with thunderbird.

According to google this is a well known problem with mozilla mailers. 
Dovecot is not lenient
with this bug in thunderbird.

Is there some workaround for this? I noticed that its possible to turn 
on some client bug workarounds for outlook.
Does the same go for mozilla?

I tried one described remedy, which was to delete the account 
information and re-register the account.
This didnt help.

The problem seems to be only with INBOX, which I have mapped to 
/var/spool/mail/<username>,
not my other imap mailboxes.

Im running gnus as well and the problem doesnt seem to occur there.

My configuration:
Redhat 9
dovecot 0.99.10.5 (from DAG repository RPM:s)

Another question: Would it be possible to run uw-imap on one port, and 
dovecot on another?
Or would that corrupt the mailstores?

Regards,
/Joakim