Try adding '-kb' to the relevant line in '/etc/X11/xdm/Xservers'. Mine says:
:0 local /usr/bin/X11/X vt9 -deferglyphs 16 -kb
The '-kb' turns off the 'xkb' hackery. Or put:
XkbDisable
in your XF86Config file. The 'xkb' stuff works great for in most cases,
but occasionally, it gets in the way.
I don't know if it'll fix your problem, but it won't take long to try.
Good luck!
-- Tovar
