Addressed through a ticket... but for others to see what the problem was, here it is:
I see the problem... it is your setup. No bugs. You need to set the EMAIL field for group registration to be used in BOTH MEMBERS & BILLING. The final page that has billing info has no name or email. You should assign firstname, lastname and email all to be both members and billing. The main email notification for the user will go to the email address for the billing contact. You are not providing a field for this email address so there is no email to send to there. It is required. Make that change and you should be just fine. Thanks.
Thanks a lot. I knew it was some minor thing. But this is something that can be missed.
I have been going crazy for last 6 days trying to fix this. Thanks for your help.
All I need now is that "special field" I mentioned to you. Then if this can be stabilized for a while...I should be fine. 1.6 compatibility would be nice as well, I know its in the works.