I find a weird thing happen with my new dolphin D7 RC installation.
Repro Steps:
a) I have a registered a member with name "BBBBBBB" with email email@gmail.com in my new D7 RC Installation.
b) Then I try use Auth Type="Facebookconnect" and try to login using this email address, email@gmail.com
c) After having done so, All My existing members were no longer shown up at the home page under Members.
I can however login to the website but when I try to upload a video or do any action, I am told access denied. I also am not able to register using any of those existing usernames.
This is a serious issue. Could you please take a look.
Please feel free to delete the post if this does not repro at your end.