[Dovecot] ssl still not working

hi, I'm just download the latest cvs and try to use imaps. in mozilla I've got the following message window:

mail.int.bppiac.hu received a message with incorrect Message Authentication Code. If the error occurs frequently, contact the website administrator.

and there is only one OK button:-) and this happens always. what can be the reason and what can I do? thanks.

-- Levente "Si vis pacem para bellum!"