UPDATE: I will
not be able to update this hack to v4.0.x until vBulletin Solutions has released vBulletin 4.0.4 which, I can confirm, does fix the bug that will not allow this hack to work at then moment (Internet Brands have advised the release date for 4.0.4 should be before the end of June 2010, so this hack will be ported asap after the release). See this bug report for more information -
http://tracker.vbulletin.com/browse/VBIV-3652.