Problem mapping a subdomain to an Aggregate site in GAE

Hi, everyone.
I have an GAE Aggregate project in at the url
Now, I bought a domain from LWS and I want to map the subdomain to
After setting up succefully all the required steps suggested by GAE (, I'm able to reach my GAE app via; but, once the page finishes loading, instead of the
new url (my hope), the old one ( still displaying in the address bar of my browser.
I'm aware that the present post is not a specific ODK post: I apologize for that
but I'm asking you in case somebody would had faced and solved such an issue.
In advance, thanks for your help.