Password plugin - Problem with HmailServer

[montik]

Hi,

I have installed HmailServer 5.3.3 and Roundcube Webmail 0.9.5 + Plugin password (original one) in version 3.2.
I have successfuly enabled the plugin, but when I try to change password it says 'Error, cannot save password'.

In log is this one =>
[17-Jan-2014 07:52:13 +0300]: Plugin password (hmail driver): Failed to create COM object `hMailServer.Application': Access is denied.
[17-Jan-2014 07:52:13 +0300]: Plugin password (hmail driver): This problem is often caused by DCOM permissions not being set.

Config of plugin is here =>
$rcmail_config['password_driver'] = 'hmail';
$rcmail_config['password_confirm_current'] = true;
$rcmail_config['password_minimum_length'] = 0;
$rcmail_config['password_require_nonalpha'] = false;
$rcmail_config['password_log'] = false;
$rcmail_config['password_login_exceptions'] = null;
$rcmail_config['password_hosts'] = null;

// hMail Driver options
// -----------------------
// Remote hMailServer configuration
// true:  HMailserver is on a remote box (php.ini: com.allow_dcom = true)
// false: Hmailserver is on same box as PHP
$rcmail_config['hmailserver_remote_dcom'] = false;
// Windows credentials
$rcmail_config['hmailserver_server'] = array(
    'Server' => 'localhost', // hostname or ip address
    'Username' => 'Administrator', // windows username
    'Password' => 'XXXXXX' // windows user password
);

Can somebody help me? It is really import for our clients to have posibility change the password after login with default one. (Changing/setting password in Hmail Administration and then logging is OK)

Thank you in advance.
JK