i didn't even know you could turn it on! i always wondered what the dot in the middle of the faces were.... and now i know... it's something to annoy the hell out of me when selecting faces :p

if it was on by default then i probably turned it off without knowing it :p

also, use the paint select tool instead of selecting all the faces one by one. i dont know why people don't use that... it's a lot easier than selecting components click by click