With all the hoopla around the release of Super Mario 3D Land and the PETA incident with it, many are ignoring another major thing that has happened with the games release. I am sure you noticed upon inserting the game the system prompted you to update your systems firmware. One of the changes this firmware made is that it now disables the flash cards that previously worked with the 3DS in standard DS mode, such as the R4 4DS Gold. The R4 team has already announced that the protection can be circumvented as shown in the video below, but as of yet has not released a patch for the cards to re-enable them to work on the 3DS. With that said, a simple bypass around this is to purchase a DS Lite, which can be found under 50 dollars at most used game shops as well as pawn shops. You'll need the DS Lite anyway to install the patch to the card after it releases.