App.Config problems

I am having curious problems with an old app that uses the WebClient class. When I try to add an App.Config file the WebRequest fails! If I remove the App.config, then it works again. I haven't been able to figure this out yet.

(Blogger has been failing while I try to post today - Error code: bX-qmyy22).

So, to recap, I was trying to add the App.config to use it to load various lists of items to go into list boxes and other settings. Hence I checked out the use of AppSettings and custom Configuration and Dynamic Properties, and so on. But they all do seem to be rather labored constructions, so I think I will abandon the App.config and instead use custom files. Rocky Lhotka gave a presentation in 2004 on the use of local storage for storing user settings, which I will look at again. It can still be found at his website