Alright, chalk this up to beta testing mac OS software.

**Answer**

The FLS for the lookup had read only checked true.

**Bug (I believe)**

- The field **or** *another field looking to the same object* **MUST** be on the layout.....



Unfortunately the beta of the new mac OS hides the checkboxes so I could not tell it was set to true....

Doh!

Thanks sanket for your answer. It got me to do some serious digging knowing that you found it working......