Camera Malfunction. Help?

Since Saturday night, my iPhone 4 camera has been majorly malfunctioning. When I start up the camera the image flickers and has lines running through it like this:


It fixed itself briefly yesterday, but today is back to the same thing. There's nothing wrong with the camera externally that I can see. My phone was jailbroken with greenp0ison when the malfunction occurred so I thought that was the issue. However, I've just finished restoring the phone and the camera still doesn't work. Anyone know what the deal is with my phone?