kernel panic in acpica

I now get the following panic with a current kernel for amd64:

acpi0: <AMIINT VIA_K8> on motherboard
acpi0: Power Button (fixed)


Fatal trap 12: page fault while in kernel mode
fault virtual address   = 0x0
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xffffffff801b4f66
stack pointer           = 0x10:0xffffffff8082a9d0
frame pointer           = 0x10:0xffffffff8082aa00
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 0 (swapper)

addr2line --exe=/usr/obj/usr/src/sys/AMD64/kernel.debug
0xffffffff801b4f66
/usr/src/sys/dev/acpica/acpi_resource.c:700

kernel is compiled without options SMP.

Sean