Looks to be dead sometimes and then alive at other times. Just keep trying!
I live in a house with children, a cat, and a dog. That equals massive amounts of time spent cleaning crap out of the carpet. Sometimes it's actual crap, other times it's coke or food, and on those rare occassions it's something I have no idea what is. Enter this, which if any indications are true, will make my life much easier.