I'm playing with the "minimum digits to send" option under fine tuning for codeset 0144 now.
I am not sure about setting this value to 0. It seems to produce inconsistent results; I suspect that it actually maintains the behavior of the previous value.
When the value is set to 1 or 2 and I tune to a channel below 100, the IR blaster sends two digits and the CM interprets this as the primary channel. E.g. I tune the DVR to channel 44, it sends 44 to the CM, and the CM interprets this as a 44-1. There's a fair delay involved but I'm not going to worry about that for now. If I tune the DVR to channel 5, it sends 05 to the CM, and the CM interprets this as 5-1.
However if I tune the DVR to a three-digit channel, the IR blaster sends three digits to the CM, which interprets it as a subchannel. E.g., I tune the DVR to 321, it sends 321 to the CM, and the CM interprets this as 32-1. Note that if I punch e.g. 022 on the DVR remote, the DVR tunes to channel 22 and then sends 22 to the CM, which interprets this as 22-1. In other words, I can't tune to subchannels of of channels 1 through 9.
In short when the minimum digits is set to 1 or 2 under codeset 0144, the program guide will work properly, but you can't make the DVR send codes for subchannels of channels 1 through 9. If the minimum digits is set to 3, the program guide is useless for OTA DTV, but you can get the DVR to send codes for all subchannels. (Subject to the "reinterpretation" issue I mentioned a couple posts up.)
I also tried using manual record with minimum digits set to 2, on the theory that this might work differently from normal tuning, but I still couldn't get it to record subchannels. E.g., entering 0022 for the channel just made the DVR tune to 22 and send 22 to the CM, which was interpreted as 22-1. However it looks like there are ways to do a manual record without tuning at all, so if you set the CM to channel you want before, this would work if you're desperate.
Sorry to dig this up, but what about splitting up the channels? Since the CM has several outputs (S-Video, Composite, RF), why can't two lineups be chosen? Say, for main channels 1-9, use S-Video on IN2, and fine tune the settings for that input to send, at a minimum 2 digits, and for that guide, remove all channels above 9. Then you can use the component for Channels 10+, on IN1, and fine tune the blaster to send 3 digits. RTV's came with two-eye IR blasters... Put both eyes over the CM IR Receiver.
I may have the minimum digits to send backwards here, but the idea is to figure out what fine-tuning is needed for single digit main channels and two digit main channels and also get the sub channels. Granted a custom guide may be needed, but that should be easy once we figure out how to tell the RTV to send numbers.