pndrev, I posed my solution to my Impulse issues in post #5
here.
RoPa, thank you for confirming. I think most people don't realize that you have to go into the Steam settings and make sure the appropriate checkbox is set to cache your userdata so Steam can run in offline mode successfully (at least now it's only one setting; it used to be two, which was maddening).
EDIT: Hacks? Hidden setting? I don't love Steam, but that's just a bit farfetched. Simply go into the settings and make sure it's set properly, and you'll never have to do it again.
At least Steam is a lot more private than SDC or Impulse, where anybody can easily launch the thing as long as they sit at your PC and see what your serial numbers are for all your applications.
-HM