lol, glad the noobs are digging up the old threads that need to get re-answered. If I remember correctly, this had to do with the safest way to fill up the bike. As in, while it's on it's side stand, or with you sitting on the bike. I know some countries don't allow riders to stay seated on the tank while filling up.
I however stay seated on the bike, and hold the spigot with both hands filling the tank to past the filler neck. This is usually right before I ride somewhere, and NEVER right when I park it (or the overflow tube will spill out a puddle of gas underneath your bike). So I'm using the top bit of the tank right away. It helps me get 300miles out of a tank.
Valid Point. I don't get off either but I like to put it down anyways.... in case of freakish tornado winds.... or some jerk who's jealous and gives me a shove... or if I look at a cute girl too long and lose my balance.... Things can happen!