sometimes I cut samples on the 2k xl, it wont save my chops

SOmetimes when I chop up a sample on my 2000xl and save, it doesnt save my chops. It will save everything else and sometimes its only the chops on one or two pads that dont get saved. Its very perplexing and annoying because it only does it some of the time. I'll spend two hours messing with a chop and then come back to find that it wasnt saved. I use zip 100 disks as my data storage. when I save I do "save all sequences & Songs" and then "save all programs and sounds". I do those in either order. What am I doing wrong? please help!!?