There seems to be a global lack of knowledge on exactly what the command line switches on mcupdate do (this is the command that runs within the mcupdate_scheduled task). There's no inbuilt help in this command, so it's very difficult to know what it's doing. Certainly the -u parameter seems to check for new package updates, but that isn't on the command my system runs, which specifically is;
mcupdate -crl -hms -pscn 15
Nothing here indicates which parameter (if any) does a guide download, and I believe one of these options also triggers an in-band check to see if there are any OTA channel changes. The package updates seem to be very US specific as well, so wouldn't apply to me anyway. One of these packages though is the seemingly random download of startresources.dll, which causes no end of problems for me when it downloads occasionally, and it's averaging about once a month at the moment.
It's difficult to believe that, after all this time, this command is still hardly understood. It's certainly responsible for waking many HTPC's in the middle of the night. I've disabled it for now, but I don't want whatever it does to start causing problems over time if it isn't running anymore.
There also used to be a documented method of controlling the time of the guide download, but I don't know if this still applies to 7MC. Anything I could find on this seemed to go back to Vista/TVPack in 2008.