Don't agonize over the occasional error. Just manually move them to the proper usergroup.

This is not an occasional error. This is every user. I just gave the latest example.

Sorry, I haven't been following. But a couple general hints: 1) Completely uninstall this mod until you're sure the stock vb registration is working. 2) Use "Search this mod" at the upper right to search for previous similar problems and solutions.

Okay I did a search within the mod and nothing similar came up.
I am going to disable the mod and verify that the native registration is working.

"- Inviter is automatically marked as referral when invited user registers using invitation code"

This is not happening. The invitee receives a link to the register.php page without any sort of ref or in invite code.

Are these questions case sensitive?

I installed this, enabled it and I see nothing "advanced" or different from the default registration.

v2.0.3 - Apr 22. 2013.
-Compatible with vBulletin 4.2.1

To upgrade:
-Import XML, allow overwrite

does this new version still work on 4.2.0?

hello,

could you please add multi - registration code generator in this plugin?
i want to generate the registration code at once, like 10 codes, so i can give to some visitors. not submit their email address one by one.

thank you very much