If you look at the rounded corners of the iTunes 4 main window, you'll see that it's not anti aliased (hold it against a dark background). Safari however, does have anti aliasing on the corners. How can this be? Don't all apps draw from the same graphics library? edit: Also, on an inactive iTunes window (greyed out), the word "iTunes" is lighter gray than other apps such as Safari and Address Book. It just looks different, maybe the anti aliasing is not the same here too.