Dan...

One slight possibilty is that someone else on your electrical grid is using the same house code and device code for something. If you have activehome software you can have it check for this. Select TOOLS, then FIND OTHER COMPUTERS. On the HOUSECODE test page you'll see, press the FIND button. It could be that a neighbor wanted their device (maybe a fan) ON at nights, but your code kept tuning it OFF. They might have been cursing till you stopped.