More news about this bug. I was just re-testing RC3 netinst in VmWare to be able sending the boottime.kmap.gz file to Denis Barbier who wanted to investigate this....and compare both boottime.kmap.gz file in 2.4 and 2.6 installs.
....and the damn keyboard works ! I'm completely puzzled. I probably need double checking of both the CD I installed from when I encountered the problem myself on my boss laptop.....and the ISO image I used in VmWare. As far as I remember the CD had been burned from the ISO image...:-)