Quite often it is necessary to just place structural pieces to create a frame construction.
One should not have to be forced to use frame generator in order to use the frame tools in order to trim members.
Please make these tools such that they work on both sides of the fence.
See attached thread.
http://forums.autodesk.com/t5/Autodesk-Inventor/Cannot-extend-member/m-p/3945121#U3945121