If you have a Win2k3 machine which already has SPS installed and you want to install SQL Server 2000 Reporting Services.
And, Even after excluding your ReportServer URL(s) from Sharepoint Server you are getting a error while opening Report Manager as -"Session state has been disabled for ASP.NET. Report Manager requires that session state be enabled."
Here is the solution...
STEP 1. Add the following to SharePoint's Web.config file (By default located at C:\Inetpub\wwwroot)
STEP 2. Now enable session state for the pages element by adding/editing enableSessionState attribute as true.
Now your Report Server Should work!