a quick and dirty workaround that has worked for me. Rename the channel to something that media center can't match to anything. For instance I have a 5.2 subchannel that wouldn't be mappable to anything on rgular or digital cable because it shows RTN (retro tv net) programming. Instead of letting it be called WOI-DT2, I called it RTN and then media center didn't map WOI's listings to it.
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