Odd mouse button behaviour

[Harald Hanche-Olsen]

In my setup, I have a trackball and a mouse. (I use the mouse almost
exclusively for the scroll wheel.) The trackball has four buttons,
numbered from left to right: 1 8 9 3. I like to have them as 1 6 2 3
instead, so I have a file containing

pointer = 1 9 3 4 5 8 7 6 2 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

(on one line) that I feed to xmodmap. This works, every time, BUT once
in a while the buttons revert to producing 1 8 9 3 again after a while
(as tested with xev). However, xmodmap -pp indicates that my pointer
settings are as I had set them. Still, running xmodmap again cures the
problem for a while.

I have no idea what triggers this, so I don't feel I have enough data
to write a PR. Does this ring a bell with any of you folks? If not,
can you suggest an experiment that might provide some more
information?

FWIW, I have these packages (on 7-STABLE as of mid-January):

dbus-1.2.4.4
hal-0.5.11_17
xf86-input-mouse-1.4.0_2
xorg-server-1.5.3_3,1

- Harald