Empty emails for imap protocol

[Mats Luspa(test pop)]

Hello!

I recently installed Cyrus-Imapd-2.1.15+Cyrus-Sasl-2.1.15+Postfix-2.0.16.
The server works fine for pop3 but for imap the new messages that is fetched
are empty even if they in the server are not.
After a reconstruct og mailboxes the messages becomes ordinary again, but
new fetched messages are empty.
The question is of course what this can depend on?

/Regards Mats (matsl at irf.se)