Users can't login once they register, logout and log back in again


When users register they get access but when they log out and then try and log back in again their login credentials no longer work. I have had a lot of people requesting reset passwords which do not get mailed to them and they have been waiting for access after paying good money for our content.

I have tried setting up a test account and can access everything fine but when I log back out and then log back in I see the account page links (not details) and the login details both appear so there is clearly a bug.

I need this looked at urgently please as our customer patience is wearing rather thin with all the issues that come with this plugin.