There are four video encoding types on DVD's. This has nothing to do with region coding which prevents you from playing DVD's from different parts of the world.
The most common in the U.S. are 24/1001 (23.9..) frames per second from 24 frames per second film, and 30/1001 (29.9..) frames per second from video tape.
Outside the U.S. countries that use 50Hz systems, use 24 fps (film) and
25 fps (video).
You can see more information at:
How the DVD player displays the different frame rates varies from DVD player to player. Most of the cheap ones have a setup option to select TV set type. You can choose between a PAL TV (all disks are output in PAL), NTSC TV (US) (all disks are output in NTSC) or Multisystem (PAL disks are output in PAL, NTSC in NTSC)
It sounds to me that your TV player is set for a multisystem TV and yours is not. You may be able to change the setting on your DVD player to NTSC only.
The best way to check is to play the DVD's using mplayer on a PC. When it starts up it tells you the frame rate in your console window.
Geoffrey S. Mendelson, Jerusalem, Israel firstname.lastname@example.org N3OWJ/4X1GM