After a system reinstall I was having the dreaded "sign-in unsuccessful"
problem with Passport. A Google search turned up several suggestions, none
of which worked until I found Dick Watson's post on Feb 7th which, among
other things, suggested re-registering msxml3.dll (regsvr32 msxml3.dll).
This fixed me!
As to what may have screwed up the registration in the first place, I can
only speculate that it may have had something to do with the fact that I
installed Visual Studio.NET 2003. Knowing how big VS is on XML, it may have
"stolen" some things from the older msxml3.dll. Again, pure speculation.