Non Admin user error on Reporting Services

I am very new to reporting services. I have completed the SQL Tutorials that come with however I am stuck on something.

My network here consists of a 2003 AD Controlled Domain, various servers yadda yadda. I obviously am a Domain admin as well as a Normal Administrator. I have deployed my report and when I, or any other member on the domain who is in the same groups as me tries to access the report it works perfectly however, when a normal Domain User tries to access the report from http://servername/reports they get the following message :-

An error has occurred during report processing. (rsProcessingAborted)
Cannot create a connection to data source 'DashboardSQL-2K5'. (rsErrorOpeningConnection)
For more information about this error navigate to the report server on the local server machine, or enable remote errors

What on earth does this mean. Once I have deployed the report I am going into Reporting Services manager and reapplying the security permissions for the Data Source but it appears to make no difference.

Anybody able to shed some light on this?

Regards

It sounds like you have configured the data source 'DashboardSQL-2K5' to use Windows credentials. In this case RS will use the credentials of the user who is running the report to connect to the data source. Do your non-admin users have permission to login to your SQL Server?

-Albert