如何阻止Internet Explorer创建新实例？

Is it a way to stop IE to create a new instance everytime it encounters a popup window? I'm debugging two Silverlight applications at the same time. The first one creates new popup window with the second one. Debugging works fine in FireFox because it does not create a separate process. But IE creates new instance and of course Visual Studio is not attached to the new instance of IE.Is it a way to stop IE to create a new instance