Can't change user password

Hi. New to OMV and surprised about this great work. Stable and powerfull. Congratulation to developers.
I installed OMV from repo "http://packages.openmediavault.org/public kralizec main" on a Debian Wheezy fresh installation.
Everything is ok at the moment, execpt that admin can't modify passwords for users. Once "Apply" is clicked, no changes on the password and users can access to Samba shares with old password, so I suppose the password didn't actually change.
Making changes via shell with "# smbpasswd {myuser}" everything is ok.
I googled for such beahviour but I didn't find anything useful.
Can anyone point me in the right direction to debug and solve this issue?
Thanks!
g