have you tried formating the card (hol start and select when starting card) the try again
i am also having a diferent problem, when i bought the card i didnt read the manual(i know i should have blah ......) and i lost the manual now and when i try load the card it dosent load just keep saying...
i have been deabiting with myself weather or not to get the dsi,because although it has 2 cameras, internet and is lighter, i have a digi camera laptop wireless internet and a ds lite but if i win this i think i will defenatly be getting one.