New Post: Using childwindow locks up visual studio 2012

I have a WPF project that overlays a child window over a Telerik RadGridView in a user control. and when I debug the project, Visual Studio 2012 locks up. This happens after I make a change to any files in the project. If I reload VS 2012 and run the project without making changes, it runs fine. The same project runs without problems if I remove the child window from the user control. The project also runs fine in Visual Studio 2010 with the child window.
I removed and reloaded Visual Studio 2012 but it still happens. I have decided to go back to VS 2010 to develop my program because I am not using anything that requires VS 2010. I am just curious if anyone has any ideas