1. An "About" page or an insert - a statement of some sort that is readily visible (e.g., FAQs, forum descriptions, homepage) - indicating that this community is maintained by volunteers may help. *These are just some suggestions.
2. Bearing the "vBulletin" name, vB customers and guests may easily mistaken this site AS an official vBulletin site. From my observation it seems while people quickly come to understand that the mods released here are offered voluntarily, they view the support forums as sections of the site to get answers to their questions (modding and standard). Both newcomers and community veterans get frustrated with the lack of replies, let alone answers to their questions.
From the (outer) appearance, vB.org looks commercial. That can be a good thing. Though, until there's clarification of what this site is all about, people will mistaken this site for something else and problems will continue to resurface.
*Mark my 1000th post here.