If you just want phpcards to use vbulletin authentication (so only members of your board can access the card site, and you don`t want to use vb templates, etc) you can use the following file in the index.php just use:
Code:
include "authvb.php";
before:
Code:
include "phpCards.header.php";
Full Credits to the original creator of authvb.php and I`m not even 100% sure if it will work, but it should do