Hi Sandy,
I run the Load Program Guide process several times and use two or three guide sources. I do an auto match the first time which covers the majority of channels. On another run, I choose the relevant guide source then manually match the channel name to the guide source name for those channels which didn't get matched automatically. It's a bit tedious. Minor variations in name strings are a PITA.
I'm not sure what goes on behind the scenes. Perhaps Yaobing can help here. I assume that if there is a XMLTV ID against each channel, the guide will be updated. I also assume that the mc2xml service will find the guide data from multiple sources.
One irritating behaviour at present is that, where you have multiple channels with the same name, MC will only load guide data for one of them from the same source. This means that you have to choose different sources (different XMLTV IDs) to get them populated.
This whole process needs to be much more reliable and simple. I don't know how WMC does it but it just works. I think they have their own guide database.
Nick.