i have a US DS and and Euro rom...i CAN play it on there, do they not have a region block? and are there PAL and NTSC DS's?
As a rule handhelds have never had region coding, since gameboy 1 you could buy a game from anywhere around the world, all the 'regions' are interchangeable, the only exception that I am aware of is on PSP Movies, they are region locked, but again, the games aren't. PAL and NTSC are a bit of a misnomer, usually it relates to the video output of the system, but in the case of hand-helds they are neither as they have there own proprietary video displays.