Check your wife's next credit card bill.
If it is the same as the T2 the box stays on the channel last viewed but many channels only air content part time and then fill the gap with shopping. You could try getting into the habit of pressing 1 on your box when you turn off your TV at night.
Thanks for the info.Maybe you have a wakeup timer set with a channel of 157? Menu -> Settings -> Time.
There are three settings here: Power On (time), Power On Channel and Power Off (time). Conceivably, if the box was set to power on at e.g. 6am with a channel of 157 and then to power off at 6:30am then that would explain what you're seeing.
When disabled it, it was on ch 124 this morning even though I left it on ch 101 last night. Its a mystery. anyway when enabled at least I can set it to 101Now disable the power off/on and see what happens again.