Farther along in this thread, I explain how to get into unlock mode. Be warned that if you drop in to some menus that are now accessable to you while unlocked they immediately start changing. The one that I'm aware of that bit me was "test 20" - "correction factor". The problem I now have is that although I know how to change it, I don't know what it was to begin with.
Ah well, sacrificed on the altar of furthering knowledge. I believe the saying is "the burned hand teaches best".
Any chance of Jim Cash riding to the rescue? Jim, you probably know what this correction factor does, but any chance you know (or can find out) what it's supposed to be on a 2000 528iA?