[RCU] Problem with password plugin

Hello list,

I have roundcube 0.3.1 configured at my mail server and it is working perfectly well. It is working with ISP style mail system based on postfix+mysql+dovecot. I like to add the password change option in roundcube. There is already password folder inside plugins folders. So it is shipped with the roundcube. I have activated it by

[............]

$rcmail_config['plugins'] = array('password');

[............]

and inside the password folder it self I have done

cd config.inc.php.dist config.inc.php

and I get a password tab in the roundcube interface. But Whenever I try to save a password; it simply throws an error as

• can't save password *

I have activated the trace log and found

[Thu Apr 08 11:05:19 2010] [error] [client 59.165.47.194] MDB2 Error: not found (-4): _doQuery: [Error message: Could not execute statement]\n[Last executed query: SELECT update_passwd('$1$w`EUn=U_$Vp1ykBH6A8vDO/rfd4HIQ.', 'test@mydomain.com')]\n[Native code: 1305]\n[Native message: FUNCTION roundcubemail.update_passwd does not exist]\n, referer: http://webmail.infoservices.in/?_task=settings&_action=plugin.password-s...

Could anyone suggest me how to fix it ?

Thanks