When selecting more than one email message to move this to another mail folder, then only the first will be moved to the destination.
When 33 where selected it informs that 33 mesages where selected, but only one is moved
Just a little more info on this case;
When moving messages from one account to another account on the same server all 33 messages where moved.
But when moving the 33 messages within the same account to another folder just one message is moved.
It must be a bug in your IMAP server. I can't reproduce this.
I have tested this whit an external provider who has dovecot 2.2.2 on board
and my server debian sqeeuze has dovecot 1.2.15-7 which has the same behavior.
Moving multiple (selected) measages to other imap account on the same or other servers is ok.
But moving multiple (selected) measages from one folder to an other folder within the same imap account will only move one message.
NB: Other version-info is
I really can't reproduce this issue.