1) Lindoz is correct in suggesting you initialise your 'newer' KN2000 back to it's FACTORY setting. I'm sorry I don't know which buttons to press, but if you have a manual, the information should be in there. If not, try asking Bill Norrie as he has great knowledge of all the Technics keyboards.
2) I would then FORMAT the new Drive using the KN2000 keyboard. Do NOT use your computer to format it.
Over the years, I have learned that if a Hard Drive, Floppy or SD Card is formatted using the PC, Technics keyboards cannot always read the data, particularly copies. So to avoid possible problems I not only format using the KN, but I also do a 'test' save, to a floppy or SD Card which in turn, set ups the keyboard and enables it to quickly recognise all future Technics data.
I'm not saying it is 'foolproof' but it is certainly worth a try.