At 10% your abs should be clearly defined and noticeable, which leads me to think that you aren't 10% bodyfat, the method you described sounds like electrical impedance method which is very inaccurate.
Go for calipers and see what you get, although this depends largely on whos doing it for you.
As for that speccial K advert, I thought the same thing, then you have to factor a few things into it, such as, women naturally have a higher bodyfat% than men as they store fat in their boobs and bum more than men, for example, a 6-pack for a bloke occurs round about 12% whereas on a women its about 18%. Also, if you look at the women in the advert shes clearly saving a few for winter, so 34% would be about right for her.