Yeah, that's the problem.
Most movies are filmed at 24 frames per second.
Home video is 29.97 frames per second.
They can either make a mess of it (like they did on VHS and Laserdiscs) by telecining to add interlaced frames or use pulldown.
Nearly all DVDs (of theatrical releases) use pulldown: The video is slowed a tiny bit to 23.976 and then flagged as 29.97. On playback, players that require it will telecine (add extra frames) to make it watchable. This is why progressive scan DVD players were such a big deal, they didn't perform this last step and threw the unaltered 23.976 frames on the screen (better video quality). (For those about to bitch, yes I know there is debate over how progressive players work, but I'm trying to keep things simple.)
Anyway, when editing DVD material IN MOST CASES you want to remove those flags or the editing software might assume it's 29.97 material and act funny as a result (Womble is the same way).
It's a simple process. I use a program called DGPulldown:
http://neuron2.net/dgpulldown/dgpulldown.html
Select your source file, set a destination file, then click the "Custom" button and type into BOTH boxes: 23.976. Click "Convert" and get a sandwich.
The software will resave a new file stripping the pulldown flags.
If there's a better way to do it, I don't know, can anyone chime in if I'm wrong here?