We have identified a possible fault with the sign-up process for Author Buzz. It only affects people signing up with email but not with WordPress.com.
The fault appears to be that the email for new accounts never arrives. Sometimes. Possibly.
Problems like this are a nightmare to debug because they do not occur consistently. All my tests show the system working so I cannot debug further on my own.
How you can help
Right now what we need is some people willing to sign up via email and report back to us. I need to figure out if the email is being sent consistently, if there is a service provider that is blocking us, or if some emails are ending up in spam traps.