I don't see anything obvious. Perhaps about the zone?
- does it extend to the walls? not off by a small amount?
- does the zone have a height?
-have you tried a different IE marker (not sure there is one off the top of my head)
Send it to tech support and see what they say.
sorry I can't be more help.
Erika
Architect, Consultant
MacBook Pro Retina, 15-inch Yosemite 2.8 GHz Intel Core i7 16 GB 1600 MHz DDR3
Mac OSX 10.11.1
AC5-18
Onuma System
"Implementing Successful Building Information Modeling"