> Damn, that's what got me. Like everyone else, upon reading of what
> Grasshopper did I tried that, but the Counter-ROTing step got me in the
> pants. Could you describe it for the curious?

Pretty straightforward, actually.

Instead of matching the numbers up frontwards (before ROTting):

1	A
2	B
3	C
4	D

(etc)

Reverse the alphabet:

1	Z
2	Y
3	X
4	W

(etc)

Then, instead of ROTting the result 7 forward, ROT it 7 backwards - so Z, for example, would ROT to H (it started at A), S would ROT to O (it started at H), etc.