Can you manually add/delete channels?
Apparently it is possible, page 43:
5. Check the signal strength on your over-the-air channels. Using your
DTVPal DVR remote control, press MENU, select Setup, System
Setup, Channel Setup, then Add a New Channel. Find a channel that
is experiencing problems, and verify that it has a strong signal.
Channels with an indicated signal strength below approximately 60 are
likely to experience loss of video.
Another interesting fact is that it requires 60 (percent?) to be able to have a stable lock. Also, there is no Canadian postal code support in the DVR, only zip codes.