I have a WPF application calling WCF via Async calls. The application has four tabs in which each are loaded from seperate async calls, each tab has a busy indicator. The problem: When running within Visual Studio I can click a refresh button on each tab and each tab's busy indicator starts and the data is retrieved from the WCF service. As each tab's data comes back it is refreshed. When I deploy the application via one click the application's UI hangs after only two tabs start refreshing. So in this case I press refresh on tab one, then on tab two and the application hangs until one of the two tabs data comes back. I thought at first that it was something to do with the WCF service throtteling and that was not the case as both the Visual Studio and the One Click deployments of the application point to the same service. Anyone have any ideas on where to look? I cannot reproduce the hang issue within Visual Studio?