After uninstalling SQL 2005 Dev version and installing Ent. Version I was unable to access the SSRS Report Manager or Report Designer applications through the default url or the full machine name url.
I received a "Application Server Unavailable"
error msg for both urls and couldn't find any solution for this problem since all the msg boards only had the problem listed without any solutions. This is why I decided to post it here in case anyone is still having this problem. MSDN has a solution for it but their page stinks since it is title "Installation problems" which I wouldn't consider this one to be and it does not contain any of the errors that would be given for any of the fixes they have listed. So no causes or symptoms which means you will not find it by searching for the error.
Here is the MSDN page with verious solutions to SSRS problems:http://msdn.microsoft.com/en-us/library/ms144289.aspx#
. The fix titled "ASP.NET must be registered with Internet Information Services" is what worked for me in resolving this problem.