App for Android - Problem execute in second plane

Hello, I have created an app for Android by Adobe Flash Professional.

This app works correctly but the problem is that I need that it could execute on the second plane.

For exemple when I receive a call of next telephone or i execute another app in my smartphone the application  stops working.

I don't know if i must change anything in the descriptor file of the application.

Someone might help please.

Thank you very much and forgive for my english that is not very good.

A greeting