Originally Posted by Ratbert
John, I have pm'd you.
Thanks Russ, I think you have the answer. When the backup is completed I'll follow your suggestion.

For the info of others, it looks like this TwinStore needs servicing, something not surprising. Unlike the other two, purchased new, this third one is a used unit with new HDDs installed, but has seen a lot of service with a dealer who had it running for a long time before it came my way.

So I'm glad I posted here to find the answer. Thank you HH and again thanks to those who took the time and trouble to respond.

John