I am breaking my teeth on that issue. I would greatly appreciate some insight:
I installed on SQL Server 2003 SQL Server 2005 SP1 with reporting services.
I converted and installed on that machine a copy of the database and the reports. Everything is working fine.
I tried then to make the reports to point to the original SQL server that is 2000 SP4. I defined a data source with the credentials stored securely in the report server (SQL authentication). I am getting that error message:
Cannot create a connection to data sources 'Sales'.(rsErrorOpeningConnection)
Login failed for user 'toto'.
I am 100% positive the credentials are right. I am 100% sure the user and the password provided are right. When I use a data source pointing on the 2005 server, it works. I tried to run the report in Visual Studio, it does the same thing.
I enabled everything with SQL Server (surface area). I have no idea where to look at.
Do you know of any setting I need to enable with Reporting server?