Warning after instal

Hi,
your plugin exactly fits my needs. But i couldn’t make it work. After installing and activation, it says:
Warning: call_user_func_array() expects parameter 1 to be a valid callback, class ‘Pbdpw’ does not have a method ‘custom_pbdpw_admin_style’ in /www/doc/www.kacirek.cz/www/wp-includes/class-wp-hook.php on line 287
Don’t you have any clue how t solve it?

Thanks, Pavel Kacirek