I newly bought Skies of Arcadia (NTSC) for my Dreamcast (PAL).
I've got the DC-X Converter that should get the game to run, but it doesn't.
I allready tried all varianties in the special menue.

Is there a way to get it running or was I tricked - 'cause the seller told me it should run...
The game starts but I get a screen that's splitted into 4 parts (don't know how to describe it better in english) sound is working - only graphic bugs.

I say return the game and complain that you got a flawed copy. If the game is new (as in wrapped) without any scratches or usage on it, then it's probably the converter or type of dreamcast you have.