One of my co-workers was upgrading a system and ran into a problem with the reports not having upgraded as expected with the rest of the system.
Strangely enough reports worked just fine out of CRM but not from within the SRS Management site. The problem was found when someone tried to access the SRS dashboard that we had built for them and it gave an error stating that the IReportViewer could not be loaded through the SRS.
So, the symptoms were reports "worked" in CRM but only CRM. Reports did not work outside of CRM, which broke non-CRM SRS reports as well as any dashboard that was referenced directly via URL.
With a bit of help from MSCRM support we were able to determine that the CRM web.config was being applied to the SRS pages since CRM and the Report Server web pages were all under the same website.
To fix the problem we moved the Report Server web pages (virtual directories) off of the CRM web site and onto a new web site on a different port. Once we did that and changed the pointers to the SRS virtual directories in CRM everything worked great.
Hope no one else has the same problem but if you do, there's hope.
Dynamic Methods Inc.