well the question would be if you are following the instructions to a T it would not shut anything down so we need to figure out what is not being followed to a T. I have an idea.
A community photo gallery - ReefTalk Gallery
If you disable your plugin system in vbulletin does vbulletin work?
If so then you have not correctly followed the instructions concerning install the xml plugins.
Lets take this one step at a time try that and lets see. it also helps provide a url to the gallery so we can see your site.