I guess we just have one of those strange in-between models. The Hitachi website doesn't even mention this model anywhere. It uses the same code as Zenith but the Hitachi codes don't work at all.
I even tried using the Zenith codes for the 4700 remote to see if that would work but onviously it didn't because doing a "power scan" didn't even work.

Oh well, I ordered a Cinema 6 yesterday.
If it works well we'll be able to use the 4700 remote on the 2700 receiver in the den because it can control the volume on our GE TV just fine.
It's rediculous to have one volume for the 2700 and one volume for the TV.
Of course I'll have to remove the antena from the 4700 because the channels would change when someone watches TV in the den :)