Hi,
These kinds of things are very difficult to work out without actually seeing the model itself. If it's not too sensitive, could you post a zipped copy of the parts of the model that are causing you trouble, or email it to support@ecotect.com and I will have someone forward it to me.
Sorry for not being able to be very much immediate help...
Andrew
--
Dr. Andrew Marsh
Ecotect Support Team
Autodesk, Inc.