I rendered using DVDA Template for NTSC Widescreen. When I watch the DVD on my widescreen TV, the picture is not anywhere close to the screen edge. Why? What can I do to make it fill up more of the screen's viewable area? In the attached image, the black border shows the remaining viewable area. Thanks!

This is either a zoom setting on your TV or perhaps the setting on your DVD player which tells the player if it's hooked up to a 4:3 or 16:9 TV.