I just came across this revitalized thread... and I remember that at the time, people were looking for me. And I never came back to this thread when I re-opened my books site. So: Here I am, and I do have a few hard SF books in my collection.
Alas,
Factory Orbit (which was mentioned a few times here) is not presently for sale, but its unofficial sequel--
Verdant Skies--is available. The "hardness" of my other novels,
Chasing the Light and
Worldfarm One, may be debatable, but I assure you they are serious SF.
My backlist is going back up, but I've had a lot of projects in the meantime, including a TV script project, and the
Verdant Skies sequel, that have drawn out the process.