The default bindings for Tk menus include the use of arrow keys to navigate menus and return or the space bar to invoke the selected item 9http://www.tcl.tk/man/tcl8.5/TkCmd/menu.htm#M77). These bindings do not seem to work with Tk Aqua on Mac OS X 10.5 (I cannot confirm whether this applies to Mac OS X 10.4 as well).
Attached is a simple script which creates a pair of menus containing dummy items and a submenu. In X11 and Windows, I can change the selected menu item with the up and down arrows and change menus with the left and right arrows. (If the submenu item is selected, the right arrow shows the cascade menu.) Pressing the space bar or return selects the items and unposts the menu.
These commands do not seem to do anything with Tk Aqua. This is noticeable because most Mac OS X applications do permit keyboard navigation with the arrows.
The specific versions I've tested are listed here. Keyboard navigation does not work as expected in the Aqua combinations but does in the other two.
8.5.0 Aqua Mac OS X 10.5.2
8.4.17 Aqua Mac OS X 10.5.2
8.5.1 X11 Mac OS X 10.5.2
8.5.1 Windows Server 2003