Thanks Michael

Not sure what was going on, last night, when I tried to Merge the eagle with a solid, it would recreate part of the surfaces that had been trimmed off. So I thought it had something to do with all those control points left over after the trim.

This morning I started from scratch , created a new surface in ZSurf, imported to MoI, trimmed it , made it solid, merged with another solid... all worked with out a hitch :)
I was done in 5mins :)

I can't bee 100% sure I followed the same steps has last night. but was pretty close... :) let's just flag this issue has "user error" :)