Thanks for the help. Ended up inserting whole file as you recommended.
I have been intouch with TC direct.
From an email received from them.
"this is an issue/bug with TurboCAD
As a workaround I would suggest that you explode the objects having Part Tree information to ACIS Solid ones and then check if the problem shows up.
This issue/bug has been passed on to the developers to be looked at and hopefully fixed but this may not be for TurboCAD 16 but for TC 17."
All I can say is the chaps at TC were very helpful just before the holidays.