When configuring RMS server integration with SharePoint, one of the tasks is to add specific rights to the ServerConfiguration.asmx file within the RMS cluster application itself.
It took me a while to figure this out, but the RMS Service Group was renamed in Server 2008. I kept browsing for the group and it kept telling me that ‘RMS Service Group’ didn’t exist… Thinking that I was going crazy I went and checked my actual service account to see who it was a member of… doh! The name had changed in 2008.
Further Information: http://technet.microsoft.com/en-us/library/cc771307(WS.10).aspx