Iphone 4, IOS 7.1.2 camera issue

Iphone 4 IOS: 7.1.2

The camera was working fine until I upgraded to IOS 5, the camera went black whenever I launch the camera app. I upgraded to 7.1.2 after it was released and it would should the view of the back camera but immediately take a photo automatically (about a second after the camera app is launched). It doesn't save the photo, and the app freezes, no response if I press any buttons in the camera app. I can quit and everything else works fine.

Anyone has a similar experience / issue?