Registration/Payment and difference between two

When a user chooses to subscribe, this sequence happens:

1. Click Subscribe, go to subscribe page where they choose their subscription package. Once package chosen, then...
2. User goes to 'Create An Account'. User clicks 'Register My Account' at bottom of this page and then...
3. User goes to Checkout page where they pay to become a subscriber (using 2 checkout for gateway). This all works great except one very important thing!

The problem: subscribers should not be able to see the data/protected pages until they have paid. In the process above, people can simply complete step two and then navigate out to the protected pages.

How do I fix this so that only people who pay can see the protected pages? Of course, I don't want people who only register and haven't paid to see the protected pages.

Where did I go wrong?

Thanks for your help!