Well I tested the script on my demo site, it seems that the feature of removing navlinks has been unavailable since the release of Mys v1.2.3. It is apparently a glitch resulted from the manipulation of mysql_fetch_array, but can be fixed easily.
To resolve this glitch, find this line from admin.php:
Replace with:
PHP Code:
if($row['id'] < 6)
Lemme know if this works for you...