Dark band on Sony Cybershot

[Colbie]

Hi

I have a Sony Cybershot DSC-W1 which is just over six months old. The last batch of photos I took have got a curved band across them which becomes narrower and more pronounced when the camera zooms in. The DSC has a large screen and I have noticed the band appears on that (I didn't notice before as it was a bright day and they weren't obvious on screen outside - it is obvious now). The band runs from top right of screen to bottom left in a convex curve, rather like a dark-shaded rainbow. I have checked the lens and can see nothing on it.

The camera has been carted about a great deal and received a few knocks (though it is cased, and in lookng at the picture history I cannot recall it being treated anything other than gently between the fine pictures and the ones that have developed the band), though only about six hundred photos have been taken with it.

Hopefully, some examples are attached.

Does anyone know what the problem might be?

Thanks

Colbie