Update: It turns out it was interfering with the MailChimp add-on. I started getting a fatal error with MailChimp somewhere in it when I added new memberships, so I disconnected the MailChimp add-on and now it seems to work.
Hope that helps.
This is happening to me too. We have upset paying customers and been called many angry names and there seems to be nothing I can do about it.
Also I just tried to update and now the plugin appears to be broken. Help?
