Problem saving with luigi's mansion

I only learned very recently that nkit files work with nintendon't, so I decided to test it out with Luigi's mansion. It seems to work fine but there are 2 problems:

1. Audio seems to not load until about 15 to 20 seconds in
2. the game recognizes my memory card but says I can't use it/it can't read it.

Anyone else having the same problem? Something I'm doing wrong? many Thanks in advanced.

"Leader of the Space Jam fan club, also the only member of the Space Jam fan club"