Working with STP files in DraftSight

I am attempting to work with a file that was originally created as a STP and then saved as a DWG file.  I can view and manipulate the object within the converted DWG file, but when I attempt to copy the object from the converted file into a new file I cannot get the object to appear in the new file.  I have tried exploding the object, etc., but still no luck.  Does anyone know a work around?