Thanks so much Salmon Trout,
I did find Robocopy.exe in C:\Windows\System32
It came bundled with Vista Ultimate 64 bit.
It is version 5.1.0.0 1027 dated 1/20/2008.
I do believe the ownership/permission problem arose from Robocopy. I was not using any other tool to write to the external drive.
The bad owners were - nobody (Unix User\nobody)
The OK owners were - Linux User,,, (EXTERNALDRIVE\everyone)
Thanks
Frank Camp