Hmph,
Really annoyed at the moment!
I thought as soon as I switched on my box that something had happened because it was tuned to channel 400 which is not where I left it last night. So, after spending about an hour putting the channels back in the order I like them, later on today, the box froze for about 15 seconds and the channels went back to the default order

. Once again I spent another hour reshuffling them only to find that about half an hour later they go back AGAIN

.
Edit:
I see Deathmaker had the same issue.