I am on 7.3.3
I did have the Twitter required set. Removing that as per the bug report cleared one of the users. The second user I had tried to manually enter before finding the bug posting. After clearing the setting, I was able to initiate a manual user creation for one. The second user returned the duplicate email address error.
It has been resolved in that he was able to register using a different email address.
The url is http://4x4wire.com/forums
I'll check my profile url....