I picked up some ready-to-bake bread at the grocery store earlier, and just about exactly an hour ago stuck it in the oven. This being the second time we have used the brand new oven.*
About 20 minutes later, I sat down to eat dinner. Just as I was finishing, Chris walked by the oven and stopped and stared at it. I apologized for leaving the light on, and he said, "No - it's still on. I hear the fan."
"I know I hit the off button."
To make a long story short, all the off button appears to do currently is change the display to its normal, oven-off, state: showing only the clock. Without changing anything else: the fan keeps on going, and, more important, the oven keeps on heating.
After about 20 minutes, we rebooted it by turning off the breaker. When we restored power, the display came up with "please set the clock" - and the fan came back on, and the oven started heating again.
(If you're interested, it's a Whirlpool KEBS208SSS02. The kicker? When Chris was shopping, it came down to this and a GE. He went with this one because of some discussion online of a problem with the GE. What problem, you might ask? Turning the oven off didn't actually turn it off....)
* It's a double oven. so technically, this was the second time we've used the upper oven. The lower oven still has packing materials in it.