I've talked to the other guys here, and unfortunately what I've told you so far is all the advice we've got. :( I really hope it's not your internal memory, because that would really suck, but I don't think it's anything with the game. You might want to try the game at a friend's house, if you have any friends with Wiis. If it IS the disc, you should probably talk to whoever you bought it from, and you should be able to exchange it.
I'm gonna mark this topic as "resolved", since I've reached the limit of what I can do for you at this point, but feel free to re-open it if you learn something else about what's going on. Hope it works out.
Data, data, data. I cannot make bricks without clay.
Alles andere ist käse.
And in case there is any confusion, yes, I do work for Aksys. If you have a questions, or care to verify my identity, you can e-mail me by putting my username in front of @aksysgames.com.