I went back to the site. RE downloaded the file for the 6th time. Opened Su and imported it at meters with merge coplanar faces checked, Checked them - all good. Selected each piece and scaled them back to mm. Checked them again. turned on the SU check and saved them. The only thing it asked me is if I wanted to save them with a non-default scale (no clue what it is talking about).
No errors this time!
I went back and did it again without merge coplanar faces and got no errors that way either.
I hate ghost problems.
I have no idea what I could have done differently the last 5 times that cause the problem.
sorry to bother u.
I hope I won’t be back for this issue again…
the only other variable is that there r 2 copies of this file on the site. I can’t remember which one I have been downloading, I think I will try the other now since I remember which one I got this time.
OK - I am going to consider that the answer—I dnld the other file and it has issues. Now to tell the author to remove that file.
thanks for ur help guys