Worked!!! Thank you.
For others: this was a firmware update to a Linkstation Duo Pro from 3.07 to 3.08 on Vista Home sp 1.
Solution was to hard connect via ethernet to the NAS and disable wireless. I am not sure if this also helped or made any difference, but I ran LSUpdater.exe as Administrator and in Compatibility mode of Windows 2000.
THanks All for your support.