Did you dump the drive's resources before and after "unlocking" it?
What does "locking" involve? Is the reduced capacity the result of a HPA? If so, did you try tools such as HDAT2 or MHDD to remove the HPA? Does the drive report that a password is set?
I notice that DiskUtil has several command options, including "Lock":
If you still have one of the drives, would it be possible for you to lock it again and compare the resources?
I notice that DiskUtil.exe contains the following text strings:
Challenge - 0x%X%X
Response - 0x%X%X
That is suggestive of password protection. Did you try ZU?
The following thread suggests that an earlier version of DiskUtil (Qunlock) actually "locked" a Maxtor drive that had not been used in a Tivo. DiskUtil was subsequently unable to undo the lock. This behaviour just adds to the puzzle.http://www.wkforums.com/forums/archive/ ... -1400.html