Prbolem in Moving the Application To Back Ground & Fore Ground

I am Bringing the Application To Fore Ground which was running the Back Ground.
Only from Home screen.(by Pressing the Numeric Key )

but the Problem is When I Press The Red Key. When i My Application is in Fore Ground

I am Getting the Home Screen. But in that Screen Expect Numeric Keys Any Key Press are not Working (For Example if Press LSk i has to Open the Contacts but that was not happening)

What May Be The Problem For This

Thanks in Advance

Praveen