problem in multi tasking program in iOS4

My application is entering into applicationDidEnterBackground method when i tapped on home button but the functions that i wrote in that method are not getting executed or called开发者_Python百科, can any one help me regarding this, I am trying this to make a application that is to run in back ground...?

Is your application one of the 3 types that CAN run in the background? i.e. Location, Music, or VoIP?

If not this may be why. If it is then what are you trying to do in the applicationDidEnterBackground method?