Loading from multiple devices

I'm having some trouble,
I've loaded my sounds,sequences,and programs from my zip drive
and then I try to load some new samples off a floppy so I can record them over the sequences loaded from the zipdrive,but it only lets me hear the floppy loaded samples when an unused sequence is selected..
I don't get it. any help would be greatly appreciated

Have you tried to save all of the sounds from your floppy onto your zip disc once you have loaded them up??

if you somehow placed a program change command in your used sequences, it will tell the mpc to switch to a specific program every time you go to that sequence. if so you should be able to delete the program change in step edit, the trick will be finding it if you got it on accident and dont know exactly where it is.