vbulletin 3 error

I have a VB4 license, however i want to downgrade my forum to vb3 as vb4 is poor and I want to intergrate the forum into joomla & magento using jfusion. Anyway to get from vb4 to vb3 I have converted the database to phpbb3 and then from phpbb3 I have used impex to import it as a vb3 database. I seem to be getting this error only on the index page - Warning: number_format() expects parameter 1 to be double, string given in [path]/includes/[login to view URL] on line 361 Warning: number_format() expects parameter 1 to be double, string given in [path]/includes/[login to view URL] on line 361 I've googled and googled and from what I have read it seems to be related to vb blogs, i dont have vb blogs installed now can I purchase it. The vb3 forum is a fresh install of the latest version with the imported database. I want to know what is causing that error and i need it fixed, not hidden but fixed. [login to view URL] Should be an easy job for someone experienced with vb3.