How do I unlock the 4 cups that have question marks on the Mario kart on the DS?

See this website for all the cheat codes for Mario Kart 7 (for the 3DS): Mario Kart 7 Cheats Codes Unlockables Nintendo 3DS IGN

Mario Party DS is a good game that will support up to 4 players at once, although, if you need more player space, Mario Kart DS supports up to 8 players. Keep in mind that each player should have their own DS to play off of, however, only one game cartridge is needed.

Have fixed this on the DSi by deleting the Mario Kart DS file using the Action Replay DSi Code Manager software. Under MY CODELISTS on right hand pane create a new file by clicking NEW then right click ADD NEW GAME type in both game code and game ID e.g. ACMP E45A2937 for Mario Kart DS. Right click Mario Kart DS and select add new cheat. The cheat codes can be copy and pasted in here.
Drag and drop the file from the right hand side to the left hand side of the window so that it appears in the memory card list. Press COMMIT CHANGES to save.

I had the same problem.
download the http://www.r4neo.com/Firmware_upgrade.rar
to upgrade your nds firmware then it will work

Pokemon White wont play on my dslite but al other games work. when is start up pokemon white both screens turn blank and the only thing that works to get this screens away is tto turn off the ds.
could you please help me with this problem i want to play pokemon white

it is corrupted whish means it wont work any more srry it happene to near enough everyone

Try an another access point.

Well... My advise is to return the game and switch it with new one!

You can find all unlockables and how to unlock them here : Click Here

look at the brass connectors, are they dirty? that could cause a problem