Why are you creating a menu that is 853x480 for a 720x480 Project?
What happens if you use one of the pre-made standard definiton menus?
If you search this a bit, you find that the 853x480 is an anamorphic SD widescreen using Apple dimensions.
Mark, as John suggests, use an Encore library menu and modify it. I assume you want wide screen SD.
Okay, I tried using both the "Blank Menu WIDE" and the "Blank Menu HD" and I'm still getting black bars when previewed.
Please post a screenshot.
You are making a DVD, so use the Wide (not HD wide).
The problem with the blank menus for this purpose, is that we cannot tell if it is the menu or your graphics that are the problem.
Use a regular library menu (just for the test purpose) so you can see if your background is different from the full menu.