This problem was solved. For others, I will post the solution that worked for me.

OK, there was an admin setting, apparently a 3rd party mod, that restricts users to only certain functions.

I found it under admin >> tools >> admin settings >> select admin name, edit permissions.

***I thought I was losing my mind*** because I tested the google mod on four different Zen carts, and even a few ficticious Zen carts that I run on localhost just for testing.

Somehow I found the clue when I copied and pasted a url from another shopping cart into the shopping cart where I wanted Google analytics, and got a persmission error.

This error message led me to search the forum, and I found a mod bu kuroi? that gave me a clue.

Sigh.