updated to Releng_6, psm0 disappeared, acpi_ibm not working

[[LoN]Kamikaze]

I just updated my Thinkpad R40 to Releng_6. The psm0 device is discovered no longer (hence no touchpad or joystick). Dmesg shows no trace of it.

Also
# sysctl dev.acpi_ibm.0.events=1
outputs:
dev.acpi_ibm.0.events: 0
sysctl: dev.acpi_ibm.0.events: Input/output error

I'd be glad about any pointers to where I should look for the cause of these problems.