Try opening your DWG in a non-archicad viewer. There are several free ones available including DWG Trueview on the Autodesk site. This way you will see what they are and can check if you are exporting correctly.
Also look on Graphisofts Help site for how to export DWGs
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"