I keep getting a "Not Ready" error sign

I recently just bought a new memory card and saved a bunch of sounds into it. However when i went to the loading screen i kept getting an error that said "not ready." It would not let me look at the files i had loaded. Does anyone know the cause of this?

Please help!!

hmm, no clue... maybe format the card in the mpc and put the sounds back on it? perhaps back the data up on the computer first?

Alright, will do
thanks for at least responding to this