i have a MZ-RH910 I've had for 1.5 yrs, use it for recording rock bands, SP BMC 12 mics, batt box, never had any problems until now bought 10 new sony HiMD (blue) disks tried 7 and only 3 worked 2 gave "rec error" at end when saving, 2 seemed to record then gave "read error" during upload to computer, now all say "can't read or record" as a test I recorded on an old disk and it worked fine bad disks or is my recorder going bad? Jim