Horizontal mouse wheel (a4tech mouse) with X ?

[Pavel Troller]

Hi!
  I'm a new owner of an A4tech X5-005D mouse. This one is equipped with two
wheels for vertical and horizontal scrolling.
  I can't make the horizontal wheel work properly. It generates exactly the
same events as the vertical one - buttons 4 and 5.
  Using xev, I've found that my mouse can generate events from "buttons"
1,2,3,4,5,4,5,8,9 - the later 4,5 generates the horizontal wheel, instead of
6,7. I don't know why.
  In my xorg.conf there is classic ZAxisMapping "4 5 6 7" line.
  I don't know, whether the mouse makers were so stupid that they created
two wheels with the same function, but I don't think so, because a program
for windoze supplied with the mouse can assign different actions to different
wheels. So where is the problem ? In the kernel layer (/dev/input/mice ?)
Or is something misconfigured in X?

  With regards, Pavel Troller