Google feed generates UPC, not ISBN

I started this thread as I have spent dozens of hours on upgrading my google feed and have read practically every thread and can't come up with a solution to be free and clear of google feed problems.

1.3.8a
google 1.10.2
numinix products fields for upc and isbn

Under google Config, I have the following set to true:
UPC/ISBN/EAN
If using Numinix Product Fields, include UPC/ISBN/EAN?

It does include the UPC, but not the ISBN in the feed and google is in critical mode nearing suspension.

The ISBN field is there in admin and on the site on the product page. Any possible clues?

Do you also by any chance have the UPC/ISBN Product Fields mod installed in addtion to the Numinix Product Fields mod? If so, remove it.

RescoCCC:

Do you also by any chance have the UPC/ISBN Product Fields mod installed in addtion to the Numinix Product Fields mod? If so, remove it.

Well that is a good trigger there.
I have been in circles with getting this going that the installation I have is not the Numinix Product Fields but the UPC/ISBN Mod along with 1.10.2 google feed.

To fix this, it appears that I need to install the NPF - you suggest to remove the UPC/ISBN, but the installation instructions require the UPC/ISBN mod?

What I first need to do is winmerge the NPF into my site, then install all NPF new files and go from there.

I have come across this on the threads:
"Numinix Product Fields
Activate Numinix Product Fields (requires separate add-on)? - this is set to true"

I do not have this option in my config? I assume this is a key element here?

Unless something has changed with NPF; from my experience in using it, only one or the other gets included in the feed. Not both. If both are present then upc dominates. Numinix confirmed one or the other in a post on his forum.