I managed to install Karmic. I didn't do something special, I just redid the install with the i915.modeset=0 for the live cd and in the grub2 options. I don't understand why it didn't work the first time.
Now I seem to have wifi connection problems. I have to look into that. I will try wicd instead of the default connection manager.
EDIT : you have to change /boot/grub/grub.cfg and had "i915.modeset=0" between "quite" and "splash" for Grub2