Moiré Patterns in G2

I paint portraits on canvas, and when I try to photograph them with my digital camera to load them on my website I frequently run into a moiré distortion. It doesn't seem to matter whether I'm shooting outdoors or in, with flash or without. Usually the moiré pattern appears on all or part of the canvas, and when it doesn't there seems to be no consistent reason why not. On Friday a friend brought her Nikon 5700 and a newer Nikon digital SLR over and she had no artifacts with any of the shots she took. With the G2, shooting at the same time, the pattern was present. You can see the problem I'm having by going to this link, which shows a painting in the beginning stages:

http://leslieficcaglia​.org/lines.htm

Any suggestions would be greatly appreciated. I bought the G2 primarily for this purpose and I'm tempted to buy a Nikon instead. However, I'd be very happy to find a workaround for the problem.

Fascinating -- like when scanning newspaper pictures. Sorry I can't help.

Yeah, it would be fascinating if it weren't so frustrating. I just read a thread in which someone who photographs houses was experiencing similar things. He doesn't say what kind of camera he's using but he had to overcome considerable skepticism from people on the forum who kept insisting that it must have been a scanned image rather than one shot with a digital camera.

He hadn't found a solution either but the last post was 2003.

It must be the same cause... The line pattern. Have you noticed if it happens with others objects that have a fine, regular pattern like that? Very odd indeedy.

Canvas is the only thing that has that effect for me. I've seen others complaining about similar problems with textured cloth, which would make sense, but no solutions are being offered. Not sure why it wasn't a problem with my friend's Nikons.