is it possible? can we play ntsc movies on pal boxes (and vice versa) smoothly without any jerky hickups?, maybe, it’s too early to say, but with xbmc’s latest option called “adjust framerate” or “dynamic framerate conversions” things surely look promising. previously, watching ntsc encoded movies with 23.976 fps on a pal xbox resulted in jerky playback under xbmc but now with this new option enabled it plays perfectly smooth, and the same goes for playing pal encoded movies (25 fps) on an ntsc xbox. be sure to try it out and let us know how you experience this exciting new option!
see this forum thread here (link) for more info