Problem with 100Hz TV and Dreamcast

[Estevez]

Hey guyz. Have bought recently new 100Hz TV and it appears, that approx. 60% of my games have "shaking/jumping" screen (like wrong frequency).
The Dreamcast is European, the TV has the NTSC through the SCART only. You have any idea what shall I do with it ?
Thanks for any suggestion.

P.S. Guy from TV store told me, that same problem but with Playstation can be fixed by simply changing/adding one cable inside the console. But another guy told me, it can not be fixed as NTSC games are at 60Hz and on 100Hz TV there is no way to play it (as when doubled it would have to be the 120Hz TV).