DS roms not working

Hi rom-ers, i'm downloading roms for the ds, some work great and some don't work at all!!! anyone know why???Post Merge: [time]1245609714[/time]
The ones that don't work say that the save game info cannot be accessed. . . . . . . . .

what flashcart are you using, what problems are you experiencing, what memory card are you using?

I'm assuming an emulator like no$gba. Please read the Common Issues https://www.romulation.org/forum/index.php?topic=1462.0 :)