WP7 compilation problem: the application cocould not be launched for debugging

During the compilation of a simple xNa program in vs express these two days, the following error occurs: "The application cocould not be launched for debugging. verify that the application is installed on the target device ".

The solution is as follows. Right-click "Configuration Manager" of solution and select "Windows Phone" in the "Active solution platform" drop-down box ". Recompile.

However, there is another situation:

When you debug the program, the error "the application cocould not be launched for debugging" is displayed. Solution: If you find that the build action of the splashscreenimage.jpg file has been changed to compile and changed to "content" and "build again", it will be OK. Is the solution http://www.touchfirst.com/Blog/65-solved-windows-phone-7-error-application-could-not-be-launched-for-debugging.aspx found at this place