Here is a screenshot:
As you can see, I'm not logged in to facebook, so vBulletin should not try to find a facebook user.
If I log out of facebook, and close my browser completely, and then open my browser, and try to register (without visiting facebook first), it works fine. It's as if vBulletin doesnt log me out of facebook, even though it says it does. As if it thinks I wanna connect through facebook, even though I dont.
Any suggestions?
(The thread you posted is 2 years old, and the issue back then should be fixed in v. 4.1.11 which I'm currently using).