Hm... Thats a problem, but I am sure there will be a way to fix the problem...! First, the harddrive is the same as in all computers around, why should yamaha put an other harddrive into this sampler??? Second, I do not own a A3000 (hey, do you wanna sell it, hee.. then email...) but I am sure, you can format the HardDrive from the sampler out, check out the disc menu, maybe you should find a format comand...! I owned a Kurzweil K2000 and if you format the HD from the computer out the Kurzweil was not able to find the HD, but, if you formatted the HD from the Kurzweil, the Kurzweil was ofcourse able to read/write to/from the HD... Hope I could help you a bit...
Frank