global_start Hook: Include External PHP File

[epic1]

In the middle of a vBulletin 3.08 -> vBulletin 3.6 upgrade.

I made this plugin for global_start:

ob_start(); 
include('C:/Inetpub/vhosts/fullthrottlev6.com/httpdocs/phpadsnew/banners/banners.php'); 
$BannerCode = ob_get_contents(); 
ob_end_clean();

And I call $BannerCode in my header. Nothing is printed. The plugin is active. Any pointers?
That's the exact path on my server, still no luck!

[pyro.699]

If you are making this a global include file. y have the ob? just have

PHP Code:

require_once('C:/Inetpub/vhosts/fullthrottlev6.com/httpdocs/phpadsnew/banners/banners.php'); 


use require_once, incase something gets ran twice

[epic1]

Just putting that in the plugin, still nothing is happening.

I'm assuming I'm keeping this in global_start.

I'm honestly shocked no one has any solutions to this problem. I hate bumping my own threads but this is the last hold up I have to put my forum live.