I just made an interesting discovery. I was checking my Timers after this morning's outage and found that, although they were all listed, the timers corresponding to the channels that were out this morning were empty - no scheduled programs within the Timers. Rebooting didn't solve the issue; even a cold boot (disconnect power - wait - reconnect power) didn't solve it.
In the end, I had to do a Check Switch test to force an EPG download, wait a few minutes, and then check my Timers ... everything was restored as it was before the outage, and I didn't have to recreate them all.
If you haven't downloaded a new copy of the EPG, you might want to take a look at the contents of your Timers. If it's all gone, perhaps what I did will help.