[snakes1100]

Did you try globally disabling all hacks and rerunning the update script?

Even though you upgraded vbulletin, sometimes simply over writing files dont achive the desired effect and sometimes can cause corruption, when file corruption already existed, i would suggest at this point seeing as you've done the basics, either nuke all the vbulletin files and reupload them or create a new folder, upload the vbulletin files again and then make the switch by changing the names of the new and old folder.

Then try a user update.