Iphone 3gs camera Shutter Won't Open?

The shutter animation stays closed for camera and video recording. I also searched online and some people say that the camera is disconnected and or it needs to be replaced. But i know its not that because i have an app called camera plus witch takes photos fine. One other person mention something about jailborken mods which could interfere.

I guess your iPhone memory is full. Delete some un important photos and then launch camera app.

Hope this works.