Well it could be just something hanging up. I would first ask you if you just updated to 7.1? Yes or no I would go ahead and reboot your device by holding down the Power button and home button until you see the Apple logo and let go, See if this clears it up, If not you can go into DFU mode which will have you hook up to iTunes and it will recognize it being in the firmware update allowing it to install a full firmware complete and then you will have to set up as new. This could take care of it as well.
Why is is is going on who knows but one of these 2 functions should work. Let us know what happens and if we need to go further we will.