Tony,

>There is an app.config in the Business project and one in the application project.
>
>I've had to modify the one in the Business project since I have two SQL Servers to access, one local and one remote, so I set up two DatabaseSets.
>
>Should the one in the application project be modified the same way, or can I just leave it alone?

It's best to keep them in synch. The app.config in the business object project is used when you test or deploy your business object project stand-alone (without a Windows or Web Forms front end).

Best Regards,