This problem is caused by the format in which the password was originally saved in the drive.
You can resolve this on at least some Lenovo laptops if the bios has a "use passphrase" setting.
When "User" or "User+Master" appears for HD password greyed out, the "use passphrase"
setting will also be greyed out, and whatever it is set to must be toggled. To toggle it, remove
the drive from the laptop, and then go into the bios settings. Remove other bios related passwords
if they are set. Now, you will be able to toggle the "user passphrase" setting, so do so.
Power down, re-insert the drive, go back into the bios, and you will now be able to set or remove
the hard-drive password.