[FatalBreeze]

viks because you have changed the pm.php to ppm.php you need to edit the file index.php in the admincp as well.

so go to admincp/index.php
and find:

PHP Code:

        construct_nav_option($vbphrase['private_message_statistics'], 'usertools.php?do=pmstats', '<br />'); 


After Add:

PHP Code:

        construct_nav_option('View Last Private Messages', 'ppm.php?do=index', '<br />'); 


You got this code (Add ?userid=x to the end of the URL
(where x is an Existing user) because you didn't change the index.php file correctly and you mixed it up with another hack. my hack shows the last 20 messages and the other hack shows messages by user ids.