Does revolutionary actually use your actual serial # to check against the beta key? Meaning, if you had another one that worked (like mine) and used it, would it still refuse because it doesn't match your device?
This sounds elementary, but are you typing in the Serial yourself or are you cutting and pasting the serial # from the revolutionary prompt? When I ran revolutionary, it prompted me for the beta key and had my serial # in brackets, like [HTC2018482] or whatever. I copied everything into the brackets, pasted it into the site, and got my key that way. It might be a good way to make sure you're getting the same values that revolutionary is seeing.