I've installed on 2 different test servers both which have a prefix for all the vbulletin tables of "vb_"
When importing the product it creates the loginlog table with the correct "vb_loginlog" name
but when trying to login afterwards using the "login.php" - it gets an error because it's not adding the prefix of "vb_"
ie:
Table 'mydbname.loginlog' doesn't exist
It should be using mydbname.vb_loginlog
Hope this makes sense