Well my dstwo has not properly worked since the day I got it and I bought it from someone second hand and not from a website so I can't really send it back. When I put it in my xl I get error and when in a ds lite it is a black retangle
Do you have eos on the sd card?? The DSTwo doesn't show up unless you have an sd card in with the system files.
EDIT: IIRC there are 3 versions of the dstwo. Unless you use the right firmware it won't work.