Microsoft Keyboard Elite for Bluetooth passkey registry fix?

Does anyone know a way to fix the registry to re-enable the "Do not use a
passkey" feature in Bluetooth Devices?
With build 5536 that option has disappeared for keyboards. I need it
simply because these keyboards/mice wont handle more than one passkey at a
time, which is a real bind in a dual or triple boot situation.
It means removing/reinstalling the darn keyboard every time I switch OS's
between Vista and XP & v.v.

--
Peter
Toronto, Canada
XP Pro SP2 X 2 + Vista Beta 5536