JDK1.1 has the limitation where Windows must be parented from Frames,
which restricts swing to always use lightweight/mediumwieght menus in
modal dialogs (a heavyweight window wouldn't be able to get input
because it would have to be parented from a input-blocked frame while
the dialog is up).

JDK1.2 AWT allows Windows to be parented directly from Dialogs, so
Swing should change the menu implementation so that heavyweight menus
are supported inside dialogs for 1.2.