I think home-ground whole-wheat flour has to have more gluten than pretty much any other flour out there...

Are you putting a whole bunch of other stuff in there? There's a reason fat is called "shortening" -- it breaks the gluten strands, and makes the bread crumbly. Unless you're putting a whole bunch of butter or some other fat into the flour, I can't imagine why it would be crumbly.

What are your ingredients?