This question seems to be a similar enough problem that the solution might work for you: [post|190826].
To save you some scrolling, here's the solution I think will help:
"Here are the steps I took to solve this problem (to the best of my ability to explain them)
- Turn off iPhone
- Open iTunes on computer
- Hold down home button on iPhone and plug iPhone USB into computer
-> (Do not plug in USB before holding down the home key)
- Click restore iPhone on iTunes and update when asked.
-> (You want a full software replacement with update)
This was clearly caused by some sort of corruption to the firmware." - ru5ty03
Good luck!