[Lynne]

Disable all Products except the vBulletin Blog and vBulletin CMS (Admin CP -> Plugins & Products -> Manage Products -> Disable) AND uncheck all the plugins except those related to the vBulletin Blog and vBulletin CMS by (Admin CP -> Plugins & Products -> Plugin Manager). You must do BOTH of those steps in order to disable all non vBulletin Modifications. (If you are troubleshooting the Facebook App, then you should leave the product "vBulletin Facebook Register Login" enabled also.)

Now see if you still have the same problem. If so, then create a new style with no parent:

• Styles & Templates > Style Manager > Add New Style
• Parent Style: No Parent Style
• Title: Default vBulletin
• Allow User Selection: Yes
• Save

Then browse the site using that totally default vbulletin style (make sure you are using this style when editing!!! It should look just like vb.com) and with plugins still all disabled - do you still have the same problem?