I know this is very late and too bad no one from Leviton replied. Makes you think that they don't browse their own forums.
I'll take a crack at your question. It there are only 2 wires in the box then you are correct - it is just sort of a switch loop probably originating from the light box and no neutral in the box. So power comes into the switch box and returns to activate the light. In this case - I would do as you suggested - connect the Black wire to the Black and the Dimmer untagged red wire to the white wire and the ground to a ground in the box. If you have a voltmeter, you could verify that the power is on the black and not coming on the white wire which would reverse your installation. I don't think you need a different dinner.
The color of the wires in your wall generally do not matter, the function does.
The simplest way to look at this install is to use the same two wires that were attached to your old device and assign one to each of the black wires of the new dimmer, catalog 6633.
That's all there is to it. there is no nuetral involved.