Apparently the DLC in Band Bros DX saves to the hard memory of the game. (Hence why it can never be deleted) This means the hardware in the card is probably different from any other DS game.
As some expected, the game will not play on any device such as the M3 or R4. Not every card has been confirmed yet, but initial tests seem to show that the game won't work on any.
That being said, I would absolutely recommend buying this game immediately (perhaps from Play-Asia?) because it doesn't seem like a fix will be out very soon due to the different hardware.
Here's the error the R4 gives:
Anyway, that's just some friendly information for everyone. Buy the game and start jamming.
~Dac
As some expected, the game will not play on any device such as the M3 or R4. Not every card has been confirmed yet, but initial tests seem to show that the game won't work on any.
That being said, I would absolutely recommend buying this game immediately (perhaps from Play-Asia?) because it doesn't seem like a fix will be out very soon due to the different hardware.
Here's the error the R4 gives:
Anyway, that's just some friendly information for everyone. Buy the game and start jamming.
~Dac
.. 
Or others 
