Software :: Movie Squashed/Cut Off In IMovie/iDvd?

I've attempted to reconstruct an old black and white film from parts off YouTube in iMovie, which has worked fine. The scenes fit together seamlessly and the subtitles are easily legible.

The problem, however, is that once I burn this via iDVD and play it on my TV, the heads of the actors are cut off at the top of the screen and the subtitles are cut off/cut in half at the bottom of the screen.

I've tried everything I can think of to correct this so that everything fits as you would expect on the screen, but so far to no avail.