When using Aperture 1.0.1 with Mac OS X 10.4.6, some images may exhibit noise, color banding, or posterization that did not appear when using Mac OS X 10.4.5.
This is a cosmetic issue, because it only affects images which are scaled to fit your screen or the Viewer. These artifacts will not appear when zoomed in to 100 percent, when using the loupe, exporting, or printing.
This issue is resolved in Aperture 1.1 or later.