I have a curious problem: My app is distributed through ClickOnce. I recently installed three new clients on a new location. They worked. After an update however, all old clients worked fine, but the three new clients did not. As my code is swallowing an exception somewhere I have been unable thusfar to pinpoint where the error lies.

When I XCopy the latest version of the app to the desktop of the three new client computers the program works fine. So, I thought uninstalling and reinstalling the program from the download location should fix the problem, but it does not!

I can think of two explanations:

• The new location has some firewall/virusscanner in place that doesn't like the latest version of my app when it is run from a standard ClickOnce directory, but it allows execution from the desktop.
• Some old settings (the app uses user scoped and app scoped settings) remain in effect after the uninstall. When I find and check the user.config file for the app however, I find no incorrect setttings there.

  Thusfar, I have been unable to reproduce the error on any other machine.

How can I solve this!?