20.45 you're right, I had not noticed that bit. Its a bit like tps on Saturday If you are interested in a particular game shown later, and you can do without the results, Its as good as live, but you can't have radio 5 on.
A PID scan is useful when looking for a channel on a certain transponder.
Instructions on page 16 of your user's manual.
If for example you wanted Budapest TV (11304H, 19540) on Amos 1W, follow the instructions and enter the VPID (700), APID (701) and PCR (700) in the approbate boxes and then scan for your channel.