recording blank screen

hi,

ever since charter switched over to using the sdv tuning adapter, i've been having a problem where if i don't view a cable channel (ie, hbo hd) for a few days, i would lose the signal when i do finally switch over to it. i watch hbo once a week for game of thrones. so most of the time, my tivo s3 is tuning on ota hd channels for both tuners. this past monday, when it recorded game of thrones, i noticed that it was recording a blank screen. i remedied by stopping the recording, and pressing channel up, channel down (which re-acquired a signal from the channel), and re-scheduled a recording from a later showing.

sometimes the channel up, channel down trick doesn't re-acquire the signal. in that situation, i have to reboot both the tuning adapter and the tivo to get back all my cable channels.

while this fixes it, it is very frustrating to not know why it's losing the signal to begin with. i can't always be there to check if there is a signal or not. i shouldn't have to do that.

so my question is: does anyone know if this is a tuning adapter problem, a cable card problem, or a tivo problem? i want to direct by question to the appropriate party.

thanks.