i know if you want to make legends in 4th gen, you need to download gen 4 pokegen. it's not enough to just put platinum in the box on the first tab there, and you actually have to use a 4th gen ID/SID. but even then you have to transfer the file from 4th gen to 5th gen to get it onto your white, using something like pokecheck.org. (link at the bottom of first post for 4th gen )