chkdsk cannot read security descriptor

I am running chkdsk on a non-system disk after a reboot and getting a couple
of errors which chkdsk is not fixing. chkdsk gets to checking the secuirty
descriptor and then says cannot read security descriptor and quits. Does the
same thing everytime I run it and gives no idea where to from there.
If anyone could help I would be grateful. Also tried running chkdsk from
safe mode as well as at startup.
Cheers