[InfiniteWebby]

Ok the problem lies in functions.php

PHP Code:

    if ($vbulletin->options['legacypostbit'] AND in_array('postbit', $templates))
    {
        $templateassoc['postbit'] = $templateassoc['postbit_legacy'];
    } 


And

PHP Code:

    if ($vbulletin->options['legacypostbit'] AND $templatename == 'postbit')
    {
        $templatename = 'postbit_legacy';
    } 


vBulletin replaces the templatename of postbit with postbit_legacy if you have the setting selected in the cp, no matter what you do before hand. So short of hacking files this sort of hack will never work with postbit_legacy selected in the cp.