I used to have a working Url Shortener with my domain 
mamma.am at 
url.mamma.am
This morning i found out that this link brings to a mysterious blank page with an "access not possible" message
No hints are found in the html code that is just
<html><body>Access not possible</body></html>
I checked the DNS and the CNAME entry 
url.mamma.am is correctly pointing to 
ghs.google.com.
I manage other domains with google apps and Url Shortener is working as it should.
Nevertheless, I cannot found the Url Shortener service among the installed app, not even for the domains where 
url.mydomain.com is still working
Any hint or support to troubleshoot this issue will be appreciated.