A bit late...
OLE means "Object Link Exchange" which refers to the Windows service that allows formatted content from one application to be inserted into another.
I don't use OLE - preferring instead to create an independent graphic file and inserted it using IMAGEATTACH. The graphic file then must accompany the drawing, which is something I am comfortable with but not always obvious to others less familiar with AutoCAD. You get much more control over the inserted object if you use IMAGEATTACH, including contrast, fade, and size. You can even include images in blocks. The attachment of the image is controlled through the External References dialog.
STF