Notebook doesn't turn off on shutdown -p now

Hi,

I have noticed something strange on my 6.0-Current. The System doesn't
power off on a schutdown -p now. At least not always. It seems to go
down normally (except it isn't able to umount /dev!?), but then it
blanks the screen and that's it. It was the same effect on a 5.3-STABLE
environment. The hardware is a Thinkpad A30p, if that matters...

Jochen