NumPad Return Key Isn't Recognized

Say I want to add a system break. There is a convenient keyboard short of simply hitting the Return key. However, the only works for the Return key above the Right-Shift key. The Return key on the number pad isn't recognized. If my right hand has been on the mouse, it is much easier to press the numpad Return rather than trying to locate the main Return key. I should be able to use either.