I have seen this when a disk from 8.x is installed in 7.3 for example. You could try "priv set advanced ; disk unfail -s x.xx" ... was this drive from a system with a higher ontap before installed in this system?
I tried disk unfail -s <disk-name> and tried wiping the label too but of no use. Initially the filer was having 8.x installed and later I reverted it to Ironcity and this caused the problem.
