when you say importing and ectracting geometry....
what software are you talking about? Are you trying to make a 3D toolpath file? Why not use STL format which is designed for machining. You will not be able to extract anything from it but that is the purpose of that format.
are you tring to create a 2D sketch by extracting edges of his model?
Why IGES. Solid works works better on the parasolid platform for orphaned solids. Or so I have been told by my reseller. I only use other formats when someone absolutely cannot read parasolid. This has only happened once and was with an asian vendor who oddly said they had an older version of SW but let couldnt get thier head screwed on straight and open almost anything we sent them.