so you're saying that the track motion squeezes the image... I thought it was actually bringing down the frame to lave a black space on top. What I did then was add a video layer of solid black and adjusted it using pan and crop to create a lower matt...Is there a better way to do what I am trying to do???

Yes it squeezes the image. Try removing the pan/crop altogether, and then you will see better what TM actually does. Pick a feature on the video that is near to the top or bottom edge, and then squash the image vertically. The feature should still be visible, indicating that there is no black frame chopping the video.

Pan/crop will give you the black bars OK, but you might need to switch back and forward between TM and pan/crop at first, until you get the settings the way you want them.

You could also use the media generators to put black rectangles on higher tracks, and use track motion on these tracks to position the rectangles as black bars on the underlying video. I suppose this way is slightly easier, because you can put the bars on the top tracks and you don't need to bother about pan/cropping anything below.

Richard