Originally and basically, when the iPhone4 is on locked screen and you quickly press the home button twice, ipod controls will appear.. But why my iPhone is not responding? Can u help me? Please...how can i restore the original home button functions?
Is the device jail broken ? If not try a hard reset by pressing both the home and power buttons at the same time. Ignore the slide to message...just keep holding them until you see the Apple logo. Don't worry that it will take longer to get to the home screen. This effectively powers down and back on the phone. That can fix a world of strange things on the iPhone.
If it's jail broken, could you hsve assigned activator to something else on the double tap?
If you're asking what "Thread moved to iPhone jailbreak" means, it means that the thread was moved from the category you started it in (iPhone 4) to the appropriate section of the of the forum (iPhone Jailbreak).