Loose Tank?
If you've ever taken your tank off, then you'll probably have deduced this already - read on and congratulate yourself! Otherwise:
Last weekend, mid-corner (and whilst it was supporting much of my weight), my tank came loose. Which was slightly alarming. Luckily the back-end of the tank was still fixed, so all that happened was the front pivoted about half an inch until it came to rest against the recessed ignition barrel. So I rode home slowly, and called my (excellent) dealer.
Anyway, it transpires that the front fixing had fractured. Now depending on how this happens, it's entirely possible for something metal to drop into the airbox. And from there it's just a short trip into the top end, which isn't where you'd choose to store a piece of shrapnel. Especially when on the move.
So the moral of the story is: If the tank suddenly slips, then stop. Quickly. And don't move off again until it's sorted! Here endeth today's lesson!