A number of people have been having problems when trying to activate there memberships after purchasing through the google checkout.
Here is a walk through of what to do:

When google okay’s the transaction they will send you a confirmation E-mail.
There should be a link on this email saying
“how do i check on my order”,
clicking this link will send you to the google checkout receipt screen, here you will find a link:
“Click here to retrieve your purchase”
clicking on this link will send you to the dingles games login screen.
here just login to your account (or create an account) to activate the membership (NB this is only active for six days)

If you have any problems, or if the six days has expired, don’t hesitate to contact me at:
paul@dinglesgames.com and I will set you up manually.

Paul