With hat tip to Mauricio for pointing out this most strange situation. It seems Microsoft is blocking users with a Gmail address from accessing the MS Live services (non MS addresses are permitted but for some reason Gmail isn’t).
The following screen tells users that some domains are “reserved”. Live, Hotmail, MSN and Passport are and seemingly Gmail is too.
The conspiracists are shrieking no doubt but there has to be a reasonable explanation for this.. doesn’t there?