Steve, I have created a custom menu for the 3rd edition (and, to answer earlier questions NO the 3rd edition does NOT have the SHOW MORE ICONS button).
This custom menu will give you access to other power saving and backlight options, etc. ....... The ONLY downside is that you will have to access these features with the custom menu, set them the way you want them and then rename the custom menu so that you have access to the default menu of the 3rd edition (the reason you should do this is that the custom menus cannot enable some of the V7 features such as Itinerary Planning, Help Me!, and Manage POIs).
Here is my webpage that descibes custom menus and my custom menu link is in the middle of the page:
>>> Custom Menu <<<