[Dovecot] quota bug

Hello i use dovecot for our mail server, it's installed on about 8 servers and it's doing really good, thanks for the great effort :-) however, i have been facing a quota problem recently, dovecot says that some users are using for example (700MB) while they are actually using (10MB), i solve this by removing *maildirsize *which solves it, is there any fix for this bug ?

thanks and regards Amr Shahin