Applets on MacOS over 800 pixels high have display problems
Try refreshing this applet a few times. Various junk, including material you have viewed in a browser, gets put in the top 50 pixels if the applet height is 850, top 100 if the height is 900 etc.
This occurs for both Firefox and Safari on MacOS. Everything is fine on Windows. Source code is here.
If you have any comments please contact Mickey Segal. A listing of many Java resources is at this link.