For Acomdata FIrewire 80 Gb External Drives - this is a firmware update that will stop the drive from disappearing when you try to initially access or format it. Once you run it, it updates software on the drive itself and makes it stable. Note than this drive, cause of its 80 Gb size, must be formatted as NTFS, not Fat32. Also do a quick format - the long format takes about 12 hours and doesn't work. Quick format works just great.