its 2.30 in the morning, hence I think you understand that I
don't want to dig deeper right now:
I built a kernel on my machine (ThinkPad X40) this afternoon
with ACPI enabled. Since this lead me straight into a kernel
panic, I commented that lines in again and built it anew.
Just a few minutes ago, I had to boot with "boot -s", and the
loader took the old kernel (/obsd), since I got the same ACPI
kernel panic again. I guess taking the old kernel when one wants
single user isn't quite intended.