The reason some are gettting an extra BBC knowledge on channel 800 is that the channel is being moved from the SDN (channel 5) mux to the BBC one. BBC Didn't originally have room for this channel on their mux, but due to better compression they now can fit it on. This should provide roon for an extra channel on the SDN mux.
Also to Johnny5, they broadcast GM** in Northern Ireland and Scotland, it covers some of the early morning programs not covered on I**2.
Hope this clears everything up.