Problems with CorelDraw X6 vectors in Corel Cad

Hi all,

I just purchased Corel Cad 2014 so that I can make 3D models out of 2D product designs.

All I need to do is extrude the 2D vectors from my CDR file.  However, when I open the file in CorelCad,

and try to extrude certain shapes, I get this error:

"Modeling operation error:  Sweep created a surface with parallel u and v".

The same object will not revolve.

There seems to be no reason that some objects work and others do not; I've tried several file formats, all of them have the same issues.

Is there some way to resolve this?  I need 100% of the imported objects to work.

Thank you for your help!

Dan