Thinkpad X20 powers on at random, 5.1-BETA2

Hi,

I've just installed 5.1-BETA2 on  ibm thinkpad x20. It has latest
bios-version and embedded controller update installed. BIOS is from 14.
February 2003 ( spsuiz9b ), embedded controller is version 1.36. I'm
experiencing that this computer boots up at random, once shut down in
FreeBSD. It doesn't matter if I use "shutdown -h now" or just power off
using the on/off button. The spontaneous boots don't seem to happen at a
specific time interval. All automatic power on features in the bios are
disabled. I've checked mailing list archives, and saw one reference about
this dated December 2002. Back then it seemed to happen to several models of
thinkpads in DP2.

I would like to know if this is something that's being worked on, or if
there are any workarounds. I'll be happy to help providing any information
needed, though I'm by all means no expert ;) Btw. I haven't yet recompiled
the kernel, so this happens with plain generic.

-
Marcin Kot