I am just putting this out there. I really think you should consider switching to XenForo (XenForo - Compelling Community Forum Software). The server loads are a LOT less and it uses and has less requirements. XenForo is also a LOT faster that most forum softwares. The only downside to XenForo are the active addon developers. Vbulletin does have a bigger developer community than xenforo since it is new. I have a XenForo license myself and I love the software.