I have a little pixel-perfect pattern image that I made. It's a 32x32 PNG image intended as a tiled desktop background / wallpaper. I use it on my Mac OS X and Windows Vista installs.
When I use it in Windows 7 as a tiled background, it looks messed up. It's no longer pixel-perfect and looks like it has some kind of filtering or moiré effect going on.
What's happening here?