Bug#492919: 40custom_load-xmodmap in Xsession(5) example does not work

[Peter Eisentraut <petere@debian.org>]

Package: x11-common
Version: 1:7.3+14

I took the example 40custom_load-xmodmap file from the man page verbatim and 
it did not have any effect.  My .Xmodmap file works if I call it with xmodmap 
directly after being logged into an X session.  The .Xmodmap file says:

keycode 160 = XF86AudioMute
keycode 174 = XF86AudioLowerVolume
keycode 176 = XF86AudioRaiseVolume

I also tried various other ways to have these settings take effect globally 
via Xsession/Xmodmap, without success.

Is this example obsolete?  Is there something else that might mess up the 
keyboard configuration?  Any clue?  Thanks.