Thanks for your reply, I'm not having much luck with this one over the weekend - you have made a few things very clear however.

I also tried Pinch/Punch and Sphering effects in Sony Vegas - promising results when the footage was frozen on one frame, but once it moves it just does not look right at all.

You would think an application or plugin for one of the editors would be available to deal with this obviously very common problem... something programmed with the maths to try and reverse the magnification/bulging effect throughout the whole picture. Something you could just increase/decrease the size and intensity of until you have cured the particular problem created by your lens size. The Vegas options are obviously not designed for this.

Cheers and regards