Can someone please help describe what moire is. A visual would be awesome but maybe its something you cant catch on a picture.

http://graphicssoft.about.com/od/glossary/l/blmoire.htm

And http://en.wikipedia.org/wiki/Moire.

Check out the TV pattern pic on that page.

A buddy of mine had this problem when the pixel structiore/SDE was interacting with the perf pattern on his screen and got moire effect at a specific image size.

Thanks for both of your help. It makes a bit more sense now.