Same issue here. Scroll speed in Geany only is very very fast. If I open the same file in a different editor the scroll speed is normal. If I go to web browser scroll speed is normal. Only a Geany / Windows issue and does not happen in Linux. Just the slightest scroll up on the trackpad will scroll like 5 lines. In another text editor even if I dramatically scroll up it doesnt move as fast as in Geany with much much less effort.