I was reading that link you posted and it says that carbon monoxide is released in small amounts by all flames. Therefore it can really build up over time from the stove and oven being left on for long periods of time.
My question is:
What about my furnace? Under normal conditions, the furnace burns 24-7 and blows all the heat through all the vents. How come burning natural gas in my furnace is not dangerous, but burning it in my stove/oven is dangerous (with respect to carbon monoxide poisoning)?
Btw, thanks for the link. It was very informative!