Despite performing pulldown on the M2V, IfoEdit produced a DVD with a frame rate of 29.97fps instead of 23.976. Therefore, the DVD had a shorter runtime than expected. Whilst this is not a problem over the course of a two hour movie, it is far from ideal for a three-minute music video!
No matter what I tried in terms of pulldown I couldn't get IfoEdit to author the DVD at the desired frame rate. Hence I tried Rejig and it worked first time! So if you're having problems with authoring NTSC movies in IfoEdit, give Rejig a whirl. The interface is practically the same.