I found my own answer to the previous-but-two question in
http://www.chrismoyles.net/mw/features.shtml
Quote"
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Half Time (2004-)
The bit of the show at about 9:05 when Chris and Dave “kick back and relax” for 10 minutes by rambling about nothing in particular. And yes, that is two thirds of the way through the show, smart arse. This bit probably infuriates Moyles-haters, but Rajar (the radio listening figures people) once revealed that this hour is the most popular in the show, ...... snip snip
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I am still not sure
why though. There must be some reason to it. Perhaps the first hour is pre-recorded!