Hacking R4 card works fine on one DSI but not on another

[kkurapika]

here's the thing - both dsi are the same model and same system ver 1.4.5U.

blue dsi - all games load perfect
pink dsi - most games load except for some which gives the white screen

few games that go white screen on pink ds but fine on blue = super Mario 64 and Mario kart.

I use the same R4 card on each so this tells me the issue lies with the pink dsi. anyone know why this is happening?

I'm baffled.