Letterboxing without my consent

Today I started importing footage of a project which is my first paid job as a videographer, and after about 140 clips it stopped automatically so I hit Apple/S to save it and a box came up saying:

Letterboxing: This may take a while.

I did not asked for all the clips top be letterboxed - something which would take at least an hour to do, and if I did want it letterboxed I know the procedure, so why is my MBP doing this without my say so?

As it happens, my camcorder has a wide viewfinder and my clients TV is a flatscreen widescreen so it may be better to have the movie in widescreen format, however I want it to be my decision - not my laptops!

It might help if you tell us what editing software you are using and what format the source material is in. Oh, and what format you told your editing software to use during the import.

I guess he's using iMovie, it does that by default cause of widescreen dominating these days. You have to turn off the letterboxing in the preferences (at least that's what I remember from iMovie 06).

^ Yes I am and thankyou - footage media is on DV cassette.

Ok, If you want a project to just look good on both widescreen and normal formats - what is the best thing to do considering there are three ways to do widescreen and any number of combinations of the following three.

1: Change project aspect ratio to widescreen when burning to i-DVD.

2: Letterboxing

3: Get a camcorder with a wide viewfinder - which they all are now these days, so by that rationale do I need to do anything to make the finished product decently viewable on an old or new TV?