Sorry for the previous test of event4 - I patched the wrong tree. :-(
event4 solves the problem for pageup/pagedown! I can scroll through half the userguide at 100% cpu, release the key, and LyX stops instantly! This is very good. The scrollbar still overshoots. I can only make it overshoot slightly when clicking the scrollbar arrows, I was not able to make LyX roll for several pages with those. This is big improvement. Only jumpscrolling using the scrollbar is still a problem. I can easily have LyX roll for several pages extra. Again, thanks for looking into this. Helge Hafting
