Login registration doesn’t work

I’m testing this ticket support system for our website, https://gigperformer.com.

I can get to the login page and register. I get an email to activate the account. However after doing so
a) I still can’t login and
b) The new username does not show up in the list of users registered at my site.

Any ideas? I’d love to leverage some of the addons available for this plugin but I’m afraid to commit to anything when I can’t even get basic functionality working.