I just got a VSPro receiver (with PVR) and do not understand what can be done with the coax input at the back labeled "In from Ant/CATV". Can I connect my cable box to this? If so, I do not see any option on my VSPro remote or in the menus to switch between my satellite channels and cable channels. To test this, I tried connecting a VCR to this input and played a movie. However, I could not see the movie on my screen. Only my sat channels are available for viewing. I am outputing my video via s-video cable. I see no reason at all for this input if I cannot view the programming via the receiver itself. What am I missing here?