My copy of HeartGold and my brother's copy of SoulSilver have gotten this message before. I merely wiped the cards off and both worked fine afterwards. The only two possibilities for this that I can think of aside from the two you mentioned is dirt/dust/anything on the game card and the system itself. With that said, if you have another DS floating about, you might want to try your game on it just to make sure that the latter's not the case.

But no, so long as it says it can't read the data you can't access it (unless you hack it or something, though I'm not necessarily going to recommend that unless you know what you're doing).

In my case I merely wiped it off with my shirt, even though it's not the greatest idea. Something similar to what you might use for cleaning a disc or a Q-tip should be decent enough.

you could try calling or E-mailing nintendo to see if theres a way to recover your save data. However I have received this error message on Pokémon pearl once or twice but I have no clue why.

DA_GLITCH  wrote:

 

Thanks, that is a possibility.

 

Could you perhaps point me in the direction of the correct Nintendo e-mail address to help me address this issue?

If you do not want to use Nintendo's 1-800-255-3700 (6 am ~ 7 pm Pacific, everyday) Customer Service number, then you could use their webform to email them.:)