Setting IsApproved to true from successful registration e-ma

I have followed the tutorial here docs.sitefinity.com/tutorial-create-a-custom-membership-provider and created a custom membership provider which is working fine in terms of storing users and their details in my custom database. 

The e-mail is sent with a link which takes you to a landing page which contains the account activation widget and a login widget on the same page. When the page is loaded it comes up with the message saying "You have successfully activated your account......" however the IsApproved flag in the database is still set to false.

 Hence, I cannot log in - any ideas on what I am doing wrong?

Thanks