Hello I'm having a problem getting the back button to go to the open application menu ( on the Windows phone it is called Back Stack I believe). I originally had the back button only close the program but when I tried submitting it to the Windows Market place, they returned my request and said I need the button to function where it will open the Back Stack where all the open apps are but I can not figure out what I need to do to make the back button perform this task. What do I need to do to amend this issue that is keeping my game off the Marketplace?

Thank you,