Chrome Version (from the about:version page): 61.0.3163.79 (Official Build) beta (64-bit)
Is this the most recent version:
OS + version: Linux
CPU architecture (32-bit / 64-bit): 64-bit
Window manager: XFCE/xfwm4
URLs (if relevant):
Behavior in Linux Firefox:
Behavior in Windows Chrome (if you have access to it):

What steps will reproduce the problem?
(1) Install imwheel
(2) Create the following ~/.imwheelrc
".*"
None,           Up,     Page_Up,   1, 100, 100
None,           Down,   Page_Down, 1, 100, 100
(3) Run imwheel
(4) Open a page that's several pages long
(5) Pull the scroll wheel down a few times

What is the expected result?
It scrolls down one page for each click until the end of the page.

What happens instead?
Most of the time, it scrolls down, then jumps right back up to where it was.

If I disable chrome://flags/#smooth-scrolling, it works fine.