Plugin not executing in custom template

[DetroitYES]

I'm running a plugin, hook location of global_start that includes the php page:

http://www.isofb.com/mb/atd_scripts/atd_right.php

I know the plugin works, because if i include it in the navbar template, the text is printed on page.

The custom template I'm trying to include it in is nested within another custom template, which is then nested in the standard vbulletin templates. I think this nesting has something to do with the problem, because i can run the plugin on a top-level custom template...

Does anyone have advice or experience with this? Here is my plugin:

ob_start();
   ob_clean();
   include('atd_scripts/atd_right.php');
   $nb_sidebar_content = ob_get_contents();
ob_end_clean();