Ok,
It is not you nor your camera.
Its your LCD.
I am using my notebook to surf internet.
This notebook at the same time is connected to another LCD so I can drag over and see it.
Over at my IBM notebook, the picture is Grainy.
When I drag the webpage over to the LCD, it is no noise at all.
And how I know which is correct? When I run my Photoshop in my IBM, it prompt me that my IBM LCD calibration is out.
Hope this help.