Vertical lines on 3G when screen is off.

[mikefletcher85]

I have recently noticed that when my screen is off sometimes I can see vertical lines on the screen. Its like the screen is on, but not (if that makes sense). When I press either the Home or Sleep button and let the screen shut off again it goes away. Anyone else know or have had the same problem. Attached are 2 pictures, one before (with the lines) and another after I pressed the Home key and let it turn back off.

Thanks