Some how, about the time the beta was put out - actually a couple days later, I noted a very odd occurrance.
I have finished my exterior mod, which encompases several exterior cells. I went on to work on the first exterior - the manor house on my redoubt and was about 80% done with that, when I fired up a save, and it started on the view of one of my imperial tower exterior statics!! IN AN INTERIOR CELL for my Manor house.
I thought that was wierd so I backed the camera away and saw that most of my exterior statics from my exterior redoubt were somehow exported into my interior cell - the entire fort - everything but the walls. The manor house, the inn, the logistics building, and all of the tower pieces with interiors (imperial tower and tower door pieces.)
That freaked me out! And I immediately backed out without saving this file corruption.
When I opened up the save from the night before, the exterior pieces were not in the interior cell. I thought everything was OK.
That was two days ago (no I didn't check the Tamriel exterior cells - didn't think there would be a problem.
I open up the CK today and it downloads the new version. I start getting errors telling me I need to finalize Navmeshes in several cells I modded in the exterior Tamriel space. Weird, I thought - I had already finalized and tested these - so take a look.
Guess what. All those exterior pieces - Angeline's Aromatics, Styrr's house, Bard college towers, East Empire Bldg, and about 8 out of 10 tower pieces are all... gone.
They are not in the saves either.
Not a killer because all the small pieces are still there. and my Interior cell seems OK; but wow!
Hope this doesn't happen to anyone else - and check your externals for large poly statics missing.

This, along with another issue,led to me putting the mod on hold. I will go back and try to solve it later, but not until I've finished the new mod I started!