This should be submitted as a suggestion on Connect:
Live Mesh Beta: Suggestions - Go cast your vote!
I've not encountered what you describe, but then my PCs are not headless. I suspect it isn't an issue with a lack of a monitor, but that a video driver needs to be installed. On the other hand, Live Mesh RD will present a message to a logged on user that someone is looking to connect before actually presenting you with the login, so that a logged in user can deny the request. If no display device is detected, it can't do this.
-steve
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