Currently Being ModeratedJan 17, 2013 6:22 AM (in response to susan3647)
Try a reset by pressing the home and sleep buttons until you see the Apple logo, ignoring the slider. Takes about 5-15 secs of button holding and you won't lose any data or settings.
If still a problem restore with your backup.
If still a problem restore as new, i.e. without your backup. See how it runs with nothing synced to it.
If still a problem, it's likely a hardware issue.