NOF support weren't too helpful. All they tell me is:
"NetObjects Fusion Essentials is a newer version than NetObjects Fusion 7. Fusion Essential has some new feature and may include unspecified updates, enhancements, and bug fixes.
Please note that, you cannot import sites created in older version of NetObjects Fusion to newer version of NetObjects Fusion."
I most definitely can, and did, open my site created in an older version of NOF into the newer version. I also published it to my local host with no problems apart from a few missing graphics. Locating them and embedding them again will fix that problem.
So, what are these unspecified updates, enhancements, and bug fixes?
Presumably someone must know. It ssems highly unusual for a software company to remain so secretive about enhancements to their software.