The team that wrote Pro SQL 2005 RS and whoever wrote BOL all say breaking out the report server databases on to a separate machine from the report server is very easy. I have tried it and it is but I can't get the report server to connect to the databases once they are on the other machine.

Everything was done by the book(s). We use SSRS only for intranet use so all inside firewall. The SQL Server 2005 services on both machines (including the RS Windows service) all run as the same domain administrator account, this account was used to log in to RS Config Tool and it was told to use this account under Windows Authentication to connect to the database server. The two machines are in the same domain, even on the same switch. The account has sysadmin rights on both SQL Servers, as well as having all the RSExecRole rights as specified in BOL. And it has rights to logon as a service in group policy on both machines.
The RS Config Tool completed fine and reported no errors.

But when you try to connect to the report server you get the error:

"The report server cannot open a connection to the report server database. The logon failed. (rsReportServerDatabaseLogonFailed)" The log shows that a privilege required by the client is missing but doesn't specify what! I thought this was all taken care of when the RS Config Tool told it which account to connect with.

This is driving me daft. It should be so easy!! Does anyone have any idea what might be wrong? Nothing says I need to do anything with the encryption key when I am keeping the report server itself exactly as it was and just moving the catalog - or have I missed something here?

Grateful for any ideas.

Replying to my own post in case of use to anyone.

I have finally fixed this problem.

The "privilege required by the client" turned out to be "Act as part of operating system" for the ASPNET user (under which the RS web service runs) on its own native machine which is Windows 2000 Server.

Since it did not require this privilege when the report server catalog was also on this machine then I can only assume it became necessary either in principle when that catalog was moved, in which case you would think Books On Line would tell you, or because they had been moved to a Windows 2003 server machine and there then appeared some obscure (to me anyway!) conflict.

I don't suppose this would be much of a fix if either of the servers involved faced the internet but they are entirely internal so I am going with it.