Yeah, I'm figuring it was that because whenever you quote a post, it puts it back into the formatting that was used, so it'll show up with all the formatting the original poster used. With HTML, it does the same thing, but a new post defaults to using only UBBCode, rendering HTML into "just more text".
This post is mostly directed at the less web-savvy users. For you and I, it might be something simple, but this should hopefully break it down for others without as much background using computers.
Gravity seems weak until you look down.