There's a section in config.php called 'PATH TO ADMIN & MODERATOR CONTROL PANELS' and here are options:
PHP Code:
$config['Misc']['admincpdir'] = 'admincp';
$config['Misc']['modcpdir'] = 'modcp'; 
Modifications of these should help, but we'll investigate it precisely, if there's anything else, what might cause the error described above.