CRM 2011 - JavaScript - Access Is Denied

While testing a CRM 2011 instance we ran into a issue where the JavaScript kept throwing an "Access is Denied" message. This only occurred on one system and no others. What we discovered was the user was looked in using the fully qualified URL ie:- http://crmtroubleshoot.blogspot.com.au While everone else was using the short URL something like the following http://crmtroubleshoot When calling the service through JavaScript we use the following getClientUrl() + "/XRMServices/2011/Organization.svc/web"; This was returning the short URL which the server thought was a different server to the long name. The user re logged in with the Short URL and the problem went away. If you have DNS suffixes set then you need to log in to CRM using the short name. I suspect (unconfirmed) if you don't have the DNS suffixes set then using the long URL should be fine.