Hello.

The following is only reproducable when
a) a cardbus (not a pcmcia) card is activated, in my case a Netgear WG511T
b) the system is powered off using the poweroff(8) (using ACPI)

The last messages from the kernel are:
[snip]
syncing disks... 4 done
unmouting [...]
[...]
unmounting / (/dev/wd0a)... done
panic: hook_disestablish: hook 0xc0d3e8b0 not established
Stopped in pid 9.1 (cardslot0) at       netbsd:cpu_Debugger+0x4:      leave
db>
[/snip]

I can, of course, also provide the boot messages, if necessary.

-- 
hernani