Camera Issue

I have 2 N97s at home - one white, one black. When you fire up the camera in the white N97, occassionally what you see are these weird lines that block the view of the object you're going to capture. It looks just like as if there is a lot of noise, but of course there isn't as I was outdoors in bright sunlight. I tried rebooting, but I still had the same problem. Then after a few hours I opened the lens cover to see if the problem has gone away and to my pleasant surprise those annoying lines have gone away. But the next day, I was encountered with the same problem. It seems as if this happens every once in a while but nothing like this ever happened on the black unit..

I'm just wondering if maybe anyone else has experienced the same issue, and if someone may know a solution to this problem.