Border on the Right when TV-OUT is on NTSC

When playing a Divx or Mpeg movie, whatever moviatype. I have a Black border on the right of the moviescreen, when I put the TV-OUT on PAL, the border is gone.. what could this be and how can I change it?

Thanx!

P.S. I use NTSC instead of PAL because my tv handles NTSC better then PAL (fullscreen)