Did you upload the files correctly? You should double check to make sure you uploaded via ftp with binary and not ascii settings, also check to make sure the file sizes match up as you may have some corrupted files. Secondly, double check the directions and make sure you did them all.
If no dice, you can disable the plugin by first disabling hooks and uninstall it that way.
http://www.vbulletin.com/forum/forum...ystem-globally