In the "set as wallpaper dialog", the position "tile" does not update the preview. This has not been implemented: http://lxr.mozilla.org/mozilla/source/browser/base/content/setWallpaper.xul#111
If we have the option available, it should work.
13 years ago
Maybe it is also a good idea to remember the last used position (center;stretch;tile).
Marking this fixed since this was tracking a 1.0 solution. I filed bug 253197 to track the real issue.