I have read through a lot of the other posts and conclude that there is a serious problem with the copy protection scheme used on this game. Fortunately I have a 14 day grace period in which to return it for a refund which I plan to do.
A real dissappointment. I have enjoyed many hours playing DD and looked forward to the new game. I will look in at the forums in a month or so to see if you issue another patch and then buy and try again.
Too bad.
Regards
Charles Romer