I just thought this might help anyone else having the same problem

I just bought a new memory stick that's the exact same one that gave me problems except the speed was 4 and I can confirm that Golden Sun plays. So I'm guessing anything lower than a 3 or 4 write speed isn't gonna play it. Thanks for the help guys, I appreciate it.

 

class doesn't really mean much as its just a guide to minimum sequential write speed.
afaik ds usage is more small and/or random read/writes.
class 2 cards may perform better than class 4/6 cards.
class is a decent indicator but isn't end of everything.