I eventually cleared this problem with HELP not opening in the 64-bit Pro 9 working the SCS. I had to do a clean uninstall of ALL Sony Creative Software applications, including making some manual registry edits, as described here:
I installed Windows x64 couple of days ago and after doing all updates I downloaded and installed Vegas 9.0 x64 - simply after the book.
As expected everything - including the help - worked flawlessly.