Found something else that affects this. The Gnome mouse control has a
touchpad tab, with checkboxes for enable vertical scroll and enable
horizontal scroll. Apparently the default is to enable vertical but not
horizontal scrolling, and it would appear that this is turning off the
scrolling. Checked
I've found a similar thing; the only option that I've seen affected is
HorizEdgeScroll, which is off by default but turned on in my xorg.conf
file. If I enable SHMConfig I can use synclient to turn it on and it
works fine, but simply setting it in the config file doesn't work. It
looks like it does
