Runlevel 6 is now reboot as it should be (System V compatibility).
You have to upgrade the scripts too, not just the binaries. Even
better, get a real distribution - and you will not have to upgrade
things by hand anymore, just install new *.deb or *.rpm packages.
Slackware seems to be dead.
BTW, this is user space problem, nothing to do with the kernel...
Marek
(using Debian Linux 1.1 beta)