Hi Dave,
To save your time, I've done a clean install on a machine and still had the same trouble. By the sounds of it this is an issue beyond any of our control. I guess we'd all better start asking Sony serious questions about how such a product got released.
I've started a thread on the Adobe Digital Editions forum and there's already a third person in the same situation as you and me.
http://www.adobeforums.com/webx/?13@...Ds@.59b67ba8/0
I'll give Sony a call tomorrow as well, if enough of us make contact perhaps they will take it seriously.
Good luck,
Mike.