Kees - Xorg ignores setting the keyboard driver in xorg.conf and forces it to evdev, thus explaining your ability to reproduce it even with "kbd" specified in xorg.conf.
Despite people not reproducing it on hardy, it may still be a bug present there - we didn't ship evdev by default on hardy, so probably few are using it. But if you set your keyboard driver to "evdev" in xorg.conf on hardy, you may be able to test if this bug is occurring there.
In any case, the attached patch from whot and mjg59 should hopefully solve it.
Turns out this is indeed an evdev issue.
Kees - Xorg ignores setting the keyboard driver in xorg.conf and forces it to evdev, thus explaining your ability to reproduce it even with "kbd" specified in xorg.conf.
Despite people not reproducing it on hardy, it may still be a bug present there - we didn't ship evdev by default on hardy, so probably few are using it. But if you set your keyboard driver to "evdev" in xorg.conf on hardy, you may be able to test if this bug is occurring there.
In any case, the attached patch from whot and mjg59 should hopefully solve it.