The Create 3D is a pretty slick tool, but beware of the condition of the 2D data you are using. I have run across numerous situations over the years where the 2D data is garbage either because of the way it was originally created or how it was changed at some point during its life.
Too many...
Go to the familiy of assemblies tab and select the member you wish and then click on "save member as" button and give it a name. This creates a new assembly file that does not have families and it is configured in the position you selected.
