Previuos versions of vbulletin
 

I'm working on a drupal based site and we would like to use vbulletin for our forums. This would be accomplished using the drupalvb module. However afaik this module has not been updated to work with version 4 of vbulletin yet and it might not happen for a good while yet. So if I purchase vbulletin is it possible to use an earlier version? I believe version 3.8 works fine with drupalvb.