So far the new version seems to work very well.
I updated to KDE 4.1.
The trick with Alt-Gr No-Dead Key is now built in. No need for own keyboard table anymore.
Setting brightness was a big pain. The add to modprobe.conf.local:
options thinkpad-acpi brightness_enable=1
and in /usr/share/hal/fdi/information/10freedesktop/10-laptop-panel-hardware.fdi
setting laptop_panel.brightness_in_hardware to false