I've mentioned this in other posts, but it's worth repeating.
Some Monsters get more false neutrals than others. Mine had its first with about 20 miles on the odometer, on the way home from the dealer while trying to pass a truck on a 2-lane road. It has had hundreds since then. The most likely are 4-5 shifts, followed by 5-6, 3-4, and very rarely 2-3. They are always due to lazy shifting on the part of my left foot, and for some reason are more likely when I'm concentrating on something else, like passing someone. (This happens occasionally with my H_onda S2000 for some weird reason as well :-[).
I've never had a problem with it when shifting to a lower gear.
I reduced the tendency to miss shifts on my bike by lowering the shift lever about half an inch using the adjuster on the shift rod that connects it to the transmission.