Configuring SQL Server Reporting Services 2005 & 2008 in same machine

When opening the Reporting Services Configuration Manager attempting to connect to a local instance, no instances are available in the Report Server Instance drop down list, and on click of the Find button i have received the below message

"No report servers were found.Details:Invalid Namespace"

Have tried using the server name (with and without domain), localhost and . in the server name field and all return the same error.

The report server is operational as I am able to deploy and run reports and connect to both the report server and manager.

The old 2005 reporting services configuration tool (I have 2005 and 2008 installed side by side, 2005 is the default instance) can connect quite happily to the 2008 reporting services instance, but obviously cannot configure from there. When you open the SQL Server Configuration Manager, select the reporting services service / properties and click the configure button it opens the 2005 tool instead of the 2008 one.

Can connect to the instance using Management studio

More feedback can be found here http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=3741006&SiteID=1

Comments
This is a known problem that occurs in certain scenarios with RS 2008 named instance when it coexists with SQL RS 2005 side by side and Microsoft are working on fixing this issue.

The workaround to fix this is

1. Open the ReportingServices.mof file and remove "RS_" from the namespaces.
For ex: If your instance name for RS 2008 is "SQL2008", replace

#pragma namespace ("\\\\.\\root\\Microsoft\\SqlServer\\ReportServer\\RS_SQL2008")

With

#pragma namespace ("\\\\.\\root\\Microsoft\\SqlServer\\ReportServer\\SQL2008")

2. Run command "MOFCOMP" from the command prompt by supplying the reportingservices.mof file name as parameter
Note that the above workaround will not solve your problem if the instance name contains any special characters. For those scenarios you need to recreate a RS 2008 instance without using special characters.

Source Link: http://connect.microsoft.com/SQLServer/feedback/ViewFeedback.aspx?FeedbackID=362738