Caulford,

The letterboxing your are referring to is a result of an
incorrect aspect ratio. When you set the properties to "Do
not letterbox", you're simply telling the program not to
render black strips above and below your final video. This
doesn't prevent the video from being stretched out of
proportion horizontally during playback, however, causing a
letterbox effect. Here's what you need to do to prevent
this:

1. Goto FILE, and click PROPERTIES.
2. Find the pull-down menu that says PIXEL ASPECT RATIO.
3. Select the appropriate ratio.

How can you tell if it's appropriate? Well, here are some
guidelines:

- The pixel ratio of a computer monitor is 1:1, so if
you're going to play your creations back on your computer,
set it to 1.000.
- If you're making a video for a DV camcorder, video CD,
etc, use any other ratio listed with the appropriate device
(make sure to check if your device is PAL (European) or
NTSC (American))

This might take some experimentation, depending on what
device you're using. Also, don't forget to check the pixel
aspect ratios on your individual clips. Keep them
consistant with your project settings. It'll make a big
differnce. I hope this helps.

Good luck, and have fun,
Nick LaMartina