Sadly we do not have a development or test environment for our Reporting Server. However, I wanted to test the upgrade from SQL Server 2008 to SQL Server 2008 R2. I wanted to know how it will affect our reports, most specifically reports that use Dundas controls.
So I asked our server admin to create me a VM for testing. I installed SQL Server 2008 database engine and reporting services, however, I had trouble deploying reports to it. It's been a while since the last time I set up reporting service so I forgot that I had to assign the System Administrator role specifically within reporting services Site Settings section. The problem is that I kept getting the error "The permissions granted to user  are insufficient for performing this operation. (rsAccessDenied) "
It turns out that the solution was to run IE as Administrator. That made the Settings page available.
Deploy still gave me the same rsAccessDenied error. The solution for that was also to run BIDS as Administrator.
Many thanks to Johan Åhlén's blog where I found the solution.