Quick Question on Recording with HR20

I looked around but just could not find an answer to this question. Regarding key word recording with the HR20, it driving me nuts that the dvr will "record" shows on channels that I don't even get. I record a lot of sports stuff and as you may know, several channels (my local, their local, another national) may be "showing" games and such throughout the day. So I might record a game on one night and by the morning, because some obscure channel is showing some coaching show (three or four times during the night), that game will be erased and replaced with nothing.

Anyway, so bottom line; is there a way to get the HR20 to only record shows on channels that I actually can see? I tried using the custom channel thing but the dvr still records stuff on the other channels. Thanks.