Jerky video when backing up Region 1 dvd's.

[kevlar69]

I've backed up many pal region 2 dvd's, but whenever I back up a region 1 dvd, the result isn't too pleasing, looking like there are frames missing or something. I realise that there is a frame rate difference between pal and ntsc, but the original ntsc disc plays back fine. I am not trying to convert from ntsc to pal, just maybe compress to fit a dvd-r.
I've tried the resulting jerky dvd-r's on other dvd players, the result is the same.

Anyone know what's going on here?

thanks in advance

Kevlar

[kevlar69]

Oh, should have mentioned, most of my backing up has been done with dvd shrink or dvd2one.

Kevlar