I'm using Word 2003. (Not my choice!) The keyboard shortcuts work normally except that Alt+O highlights but does not open (descend) the Format menu. I have to use Alt+O, Enter, to open the Format menu.
There are no other (added) menus that are also shortcutted with Alt+O. Repeated presses highlight, then un-highlight the word "Format" in the menu bar.
Anyone have an idea why this might be happening?