Problem with app on device

When I run my app with simulator every thing is ok.also when i run it on device (ipod touch 3G) for the first time,i have no problem but if i close my app and run it again,it hangs(no button working & just i can uninstall it) and if i try to minimi开发者_如何学Goze it ios seems out of action(every thing is being black)

how can i solve this problem ?

Run your application in the simulator with the profiling tools, making sure you check for allocations / releases and if there are any network resources left open.

You haven't said anything about what your app does to give any more help than that, but the development tools will tell you what is going on.

Also when you connect to the iPod, check the crash reports to see what happened

have u release any object in appWillTerminate. may be u trying to release object that is already released before the application quit. or u can see the application quit status in nslog if status is not 0 means application is not quitting properly.