Racers have been reporting something wacky about the full-drive-by-wire throttle used on the ZX10R and ZX4R (same part). It's something like only allowing a quick-downshift if the throttle is being forcibly closed. I'm not sure how much of a real-world issue it is, or whether it's just a "something", and the description of the circumstances might not be 100%.
If this is the situation, it should show up if you request a part-throttle downshift, e.g. you start climbing a hill in a high gear and want a downshift as the hill gets steeper. This isn't something that would ever happen in racetrack use...
