Finally got my hands on a Logitech Dinovo Bluetooth Desktop, and all I can say is WOW! Installed without a hitch (after removing the MS stack), works perfectly, including the ability to use the keyboard before Windows boots up. The version of Widcomm stack is 1.4.2.21.
I've also been able to share the modem successfully from my desktop machine, at the same time as the mouse/keyboard are connected - no issues.
Yes, it's expensive, but SO worth it!
Buy one!!!
Tom