Since the stand alone Tivo's are SD, they do not have a guide for digital OTA channels. Tivo understands the analog versions with an analog antenna and cable, but not it's digital counterpart: 4-1, 6-1,10-1, etc. The "-1" causes the guide issue. Technically, Tivo should be able to work with the guide provider to create code which would pull the guide data from its analog counterpart. This would take some work, since digital channels have RF numbers and they would have to map it out per region. Also They would need to have Voom mapped out per region and treat it as if Voom where carrying locals over the satellite, much like DirecTV. In other words, we would need to have Voom mapped out per region in the Tivo boxes via zip code.
Voom customers would need to make enough noise for Tivo to do this application change. Since I have had ReplayTV in the past, I have to say Voom customers are fortunate to even have Voom listed in the setup. ReplayTV does not include Voom as a choice at all, and requires software hacks and networks in order to get it to work. As Voom grows, I am sure Tivo will have to make this application change.
It might not be a bad idea to call Tivo, and check to see if and when this change is scheduled. Things have been a little hectic at Tivo lately, so it would be interesting to see how they respond.