How do you record it to the media box? I must have another look at mine to figure it out, I only packed it away a while ago as my new TV plays from an external hard drive anyway.
If your media box supports recording TV, the manual will describe how to do this. Not all media boxes will offer this functionality, lower end models tend to be playback only.
For boxes that do support it, it's just like operating a VCR. Feed the signal from the UPC signal output into the media player's input ports, start playback on the UPC box and hit record on the media box.
Leo