Sounds like the fields in your duplicated portal are still from the original table occurrence instead of the new one you created for this second portal.
Yes that was the problem. It seems fields copied from a portal retain some invisible love for that original portal ;-)
I deleted all the fields (fields copied WITH the original portal) and re-created them 'new' in the (.....copied but re-directed to a different relationship) portal, and everything works now!
THANKS PHIL !!!
It's not invisible. If you click a field while in layout mode, the display data from box on the Inspector's data tab will show:
Before you deleted and added fields, the fields in your layout showed the table occurrence name of the original table occurence in this box. The fields you have added show the table occurence name of the additional occurrence that you added for the new portal.
Instead of deleting the fields, you could have double clicked each while in layout mode to re-open specify fields. Then you could have selected the new table occurrence from the drop down list of "tables" in the top of this dialog. Since these are two occurrences of the same table, the correct field would still be selected when you did this.