Keyboard ibook

[Peter Sperisen <psperisen@freesurf.ch>]

Hi all,
I have an ibook of the newer generation with an 800MHz processor and an 
ATI Mobility Radeon 7500 graphics card. I have installed the Ben Kernel 
2.40 and XFree86 v.4.2 plus the patched drivers from Michael Dänzer. The 
X sytem works fine. My problem now is that I have a swiss-german 
keyboard. In the XF86Config-4 config file I have the following line for 
the keyboard layout:
Option        "XkbLayout"     "de_CH"
However, certain keys did not work. So I started to find out the 
keycodes using xev, and to write an .Xmodmap file to map those keys. 
Again, the solution only worked halfway through. Some keys could be 
mapped but not others. Interestingely I cannot map any key with 
adiaeresis, udiaeresis, odiaeresis etc. whereas I can map the same keys 
with anything else.
Does anyone have any idea what is going on?
Thanks for your help
Peter