Lower Split Voices

[meyrick]

Hi All. Can anyone please help with loading Jason Lee's Lower Split Voices. I can load them into the 1gb expansion board as per the instruction which came with the files. Problem is, they will only play on the Tyros 4, but not on the lower Piaggero NP31. I'm obviously not doing something correctly, but can't work out what. 
Any help or suggestions would be very much appreciated.
Many thanks in advance
meyrick