I think that SBS changed its digital channel names (to "SBS ONE" and "SBS TWO") over the weekend, which apparently caused me to lose all guide information for SBS, in turn resulting in my SBS series recordings all reporting no upcoming programs.
To fix this, I had to go back to "Add Guide Listings to Channel" and relink the "new" SBS ONE and SBS TWO to "SBS" and "SBS 2". Even then, my existing SBS series recordings did not pick up their programs from the guide even after two days of guide updates, so I re-entered all of my SBS series recordings and deleted the originals. (All of these recordings were set up in MCE, I do not currently use Interactive to set or maintain recordings.)
All now seems to be OK again, but I was surprised that this happened given that there has been no change in the digital channel numbers. If I had not noticed, or had been away, then all of my SBS series recordings would have been missed.
Has anybody else had this problem? Could there something wrong with my setup that has caused this, or are we really all at the mercy of the broadcasters -- if they change their channel names, we lose our guide data?!