troubleshooting page fault/kernel panic

[Streiner, Justin]

This is a freebsd 5.2.1 system.  Sometimes, when copying large amounts of
data from the network, the machine will page-fault, spit out some errors
and reboot.

Any insight as to what could be causing this and what I can do to fix
it would be greatly appreciated.  I can also provide more details on the
hardware if needed.

/var/log/messages shows the following from the event that caused the
reboot:

May 16 18:32:20 whammy kernel: Fatal trap 12: page fault while in kernel mode
May 16 18:32:20 whammy kernel: cpuid = 0; apic id = 00
May 16 18:32:20 whammy kernel: fault virtual address	= 0xf0db264b
May 16 18:32:20 whammy kernel: fault code		= supervisor read, page not present
May 16 18:32:20 whammy kernel: instruction pointer	= 0x8:0xc064f2a7
May 16 18:32:20 whammy kernel: stack pointer	        = 0x10:0xd77ccc48
May 16 18:32:20 whammy kernel: frame pointer	        = 0x10:0xd77ccc6c
May 16 18:32:20 whammy kernel: code segment		= base 0x0, limit 0xfffff, type 0x1b
May 16 18:32:20 whammy kernel: = DPL 0, pres 1, def32 1, gran 1
May 16 18:32:20 whammy kernel: processor eflags	= interrupt enabled, resume, IOPL = 0
May 16 18:32:20 whammy kernel: current process		= 45 (swi7: task queue)
May 16 18:32:20 whammy kernel: trap number		= 12
May 16 18:32:20 whammy kernel: panic: page fault
May 16 18:32:20 whammy kernel: cpuid = 0;
May 16 18:32:20 whammy kernel: boot() called on cpu#0
May 16 18:32:20 whammy kernel:
May 16 18:32:20 whammy kernel: syncing disks, buffers remaining... 3233 3233 3233 3233 3233 3233 3233 3233 3233 3233 3233 3233 3233 3233 ath0: device timeout
May 16 18:32:20 whammy kernel: 3233 ad1: WARNING - WRITE_DMA interrupt was seen but timeout fired LBA=6728498
May 16 18:32:20 whammy kernel: 3233 3233 3233 3233 3233 ad1: WARNING - WRITE_DMA interrupt was seen but timeout fired LBA=6728498
May 16 18:32:20 whammy kernel:
May 16 18:32:20 whammy kernel: giving up on 2914 buffers
May 16 18:32:20 whammy kernel: Uptime: 2h24m54s
May 16 18:32:20 whammy kernel: ad1: WARNING - WRITE_DMA interrupt was seen but taskqueue stalled LBA=6728498
May 16 18:32:20 whammy kernel: ad0: WARNING - FLUSHCACHE interrupt was seen but taskqueue stalled
May 16 18:32:20 whammy kernel: ad1: WARNING - FLUSHCACHE interrupt was seen but taskqueue stalled
May 16 18:32:20 whammy kernel: Shutting down ACPI