iPhone 4 home screen goes black after calls, but still responsive.
Occasionally when a phone call is ended, either by myself or the other person, the screen goes black, except for the white bar at the top with the signal and time etc. It shows me the remaining call balance over this and when i dismiss this message i'm left with the black screen.
The funny thing is, the screen is still responsive; if i double tap the home button, you notice the screen adjust slightly to show you the apps currently running, except all i see is a slightly different black screen. I can also take screen shots and you hear the noise and see the white flash (see link at the bottom for the images)
I have to either hold down the home button until voice control opens or lock the phone and then unlock it again.
It seems to me that everything is working except for the home screen displaying my background or apps.
I have two images below that show you both states of the black screen. Any help would be greatly appreciated. Thanks for your time.
http://www.dropbox.com/gallery/10828474/1/Public%20Photos?h=6d2f03
iPhone 4, iOS 4