MPC2000/XL to MPC4000 to MPC2500......please help?

I've searched and can't quite find a definite answer to my questions.

I'm from and MPC2000/2000XL & MPC4000. How can I get my sequences & programs to load up correctly? I have tried to save all my sequences and programs one by one which works but when I load the program(s) individually the sounds seem to load up on the right pads but the sequence's tracks now play a different sounds. Do I need to change some sort of pad assignment?

Also, I'm currently using JJ OS-XL 3.27 is there something I need to do special because of this OS? Do I need to go back to an Akai OS to get things to load right?

Thanks

Just a guess, but the mpc2k/XLs pad assignment is funky as hell. Probably need to reassign the pad layout.

Do I reassign as in regular to chromatic or just change each one, one by one?

However it's laid out on the 2500, I've never owned or used a 1000/2500/JJOS so an owner of that machine can chime in... But it should tell you the numerical note assignment for the selected pad in the program parameter section of the OS.