Using ATI 650Pro TV tuner with Vista

I am relatively new to Vista but liked what I saw with multimedia capabilties for a rig I am building for my sister. I have an ATI-powered Theater650 TV tuner card installed. It has two coax connections. One is for regular cable and the other is a DTV/FM connection. I have the coax cable from the wall going to the cable connection and an OTA antenna connected to the DTV/FM connection. I tried detecting TV signals from Vista Media Center and all it gave me was the regular cable connection. My question is how do I get it to see the DTV connection? Do I have to choose one or the other for recording TV? I have the drivers installed but see nothing in Control Panel or Catalyst Control Center that allows me to enable/disable/choose anything. Thanks for any help.

I think I may have been a bonehead. Someone please let me know if I have. The 650 I have is a single tuner card (although it has two connections) so you can use one or the other, but not both. I think the simplest thing to do is to unplug the cablwe connection and try to detect the antenna connection.