iTunes for Windows behaves in a 'non-standard' way when compared to other Windows applications.

When I access my Windows desktop through VNCViewer, iTunes seems reluctant to repaint itself when the screen display changes (to show the countdown of the remaining time, for example). I have to trigger the repaint manually by clicking a menu option, searching for a song by typing its title in the text field and so on.

As an aside, VNCViewer under xdm is much slicker/faster than under gdm. The Windows desktop feels almost like I am operating it directly.