I cannot edit an AutoCAD dwg made with Inventor. why, and how do i get around this?

There are two ways for saving DWGs from Inventor.
 
When you use DWG (instead of IDW) for your Inventor drawing sheets, Inventor saves its part objects as blocks (to keep associativity). Such DWG files are not intended to be heavily edited in AutoCAD (TrueConnect).
 
If you want a copy of your Inventor drawing sheet to be edited in AutoCAD as AutoCAD entities, use the Save Copy As command and save your drawing sheet as "DWG for AutoCAD". Such files use layer and style mappings to display plain AutoCAD entities the same way as in Inventor.

The only 'Save as type' i can save as is 'Inventor Drawing Files (*.dwg)
The option you speak of is not availble

No, you should use Save copy as - see the tip:
http://www.cadforum.cz/cadforum_en/cannot-edit-dwg-files-from-inventor-in-autocad-tip6816

Ah-Ha!! I got it!
apparently I need to type 'group' into the command line, then remove all geometry from the group.
Thanks! This forum is great!!