Is there a possibilty to just configure SQl Server Reporting Services 2008 and this is coonnected to Reportserver and ReportserverTempDB is on SQL Server 2005, or the Reportserver and ReportserverTempDB has to be on SQL Server 2008.
If you are doing the former you should be in a development box and not production, if you need that setup for production call Microsoft so you are not violating any licensing issues. I have explained what I know in the last post of the thread below.