Fatal trap 12: page trap while in kernel mode

[Chris Hastie]

I have a nasty feeling that this may be a hardware problem rather than
FreeBSD, but any pointers appreciated.

Over the last couple of days, with no changes in configuration, one of
my boxes has started to die with increasing frequency, throwing up
errors like this:

Fatal trap 12: Page trap while in kernel mode
Fault virtual address           = 0x2c2
fault code                      = supervisor writ, page not present
instruction pointer             = 0x8:0xc0272faf
stack pointer                   = 0x10:0xd54e8cf4
frame pointer                   = 0x10:0xd54e8d0c
code segment                    = bas 0x0, limit 0xffffff, type 0x1b
                                = DPL0, pres1, def 32 1, gran1
processor eflags                = interrupt enabled, resume, IOPL = 0
current process                 = 15 (random)
trap number                     = 12
panic: page fault
syncing disks, buffers remaining... panic: free locked buf
Terminate ACPI

Although it announces that it is about to reboot, it just goes to a
blank console in which even the reset button has no effect (actually it
does cause the HDD LED to flicker for a few seconds).

Increasingly, cycling the power goes to the same foreboding blank
monitor without even a murmur from the BIOS, let alone an attempt to
boot FreeBSD.

All the hardware is around two months old - an MSI KM2M motherboard with
AMD Athlon 2200, 512MB RAM and 2 x 60 GB HDD in software RAID 1 using
Vinum. FreeBSD is 5.1 RELEASE.
-- 
Chris Hastie