> What does xev say about the up-down scroll wheel?  Is it by chance on
> buttons 7 and 8?  If so, you can just invert the 5-6 and 7-8 pair in
> the zaxismapping.

It says nothing.

That's why I posted. I have edited my XF86Config to tell XFree the mouse
has 8 buttons. Then I tried to use xev to see if there were any events
produced
for scrolling up or down the little button on the mouse. Nothing happens.

If I scroll left or right, I see events for buttons 5 and 6 but scrolling up
or
down produces nothing.

It's by checking the first console that I discovered the mouse either
reports
only having 6 buttons (4 buttons + Z dir) or the mouse has 8 buttons but is
seen as having 6 by NetBSD's kernel (and I trust the kernel more than what
the mouse reports on the USB bus).

--
unzip ; strip ; touch ; grep ; find ; finger ; mount ; fsck ; more ; yes ;
fsck ; umount ; sleep