freebsd current crash

Hi,

I have a situation where this machine crash after working few days.
The board model is Asus P4P800-VM. What might be the problem?

I am also not able to cvsup and buildworld because of the following error

===> rescue
cd: can't cd to /usr/src/rescue
*** Error code 2

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.


some messages about the crashes etc.
-----------------------------------------------

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x8
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xc05740fa
stack pointer           = 0x10:0xdfe29acc
frame pointer           = 0x10:0xdfe29ae4
code segment            = base 0x0, limit 0xfffff, type 0x1b
                         = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 36 (swi1: net)
trap number             = 12
panic: page fault
at line 819 in file /usr/src/sys/i386/i386/trap.c
cpuid = 0;
boot() called on cpu#0

-----------------------------------------------

Fatal trap 12: page fault while in kernel mode
cpuid = 1; apic id = 01
fault virtual address   = 0x8
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xc05740ab
stack pointer           = 0x10:0xdfe29acc
frame pointer           = 0x10:0xdfe29ae4
code segment            = base 0x0, limit 0xfffff, type 0x1b
                         = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 36 (swi1: net)
trap number             = 12
panic: page fault
at line 819 in file /usr/src/sys/i386/i386/trap.c
cpuid = 1;
boot() called on cpu#1

-----------------------------------------------

Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
         The Regents of the University of California. All rights reserved.
FreeBSD 5.2-CURRENT #0: Fri Feb  6 13:59:01 EET 2004
     toor_at_proxy.ispro.net.tr:/usr/obj/usr/src/sys/PROXY
Preloaded elf kernel "/boot/kernel/kernel" at 0xc075a000.
Preloaded elf module "/boot/kernel/splash_bmp.ko" at 0xc075a21c.
ACPI APIC Table: <A M I  OEMAPIC >
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel(R) Pentium(R) 4 CPU 3.06GHz (3059.01-MHz 686-class CPU)
   Origin = "GenuineIntel"  Id = 0xf29  Stepping = 9
 
Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
   Hyperthreading: 2 logical CPUs
real memory  = 2142437376 (2043 MB)
avail memory = 2094571520 (1997 MB)
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
  cpu0 (BSP): APIC ID:  0
  cpu1 (AP): APIC ID:  1
ioapic0 <Version 2.0> irqs 0-23 on motherboard
Pentium Pro MTRR support enabled
VESA: v3.0, 3904k memory, flags:0x1, mode table:0xc06d8260 (1000040)
VESA: Intel(r)865G Graphics Chip Accelerated VGA BIOS
module_register_init: MOD_LOAD (splash_bmp, 0xc0755810, 0) error 2
acpi0: <A M I OEMRSDT> on motherboard
pcibios: BIOS version 2.10
Using $PIR table, 11 entries at 0xc00f5420
acpi0: Power Button (fixed)
Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
acpi_timer0: <24-bit timer at 3.579545MHz> port 0x808-0x80b on acpi0
acpi_cpu0: <CPU> on acpi0
acpi_cpu1: <CPU> on acpi0
pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0
pci0: <ACPI PCI bus> on pcib0
agp0: <Intel 82865G (865G GMCH) SVGA controller> port 0xefe0-0xefe7 mem 
0xfe780000-0xfe7fffff,0xf0000000-0xf7ffffff irq 16 at device 2.0 on pci0
agp0: detected 3964k stolen memory
agp0: aperture size is 128M
pcib1: <ACPI PCI-PCI bridge> at device 30.0 on pci0
pci1: <ACPI PCI bus> on pcib1
fxp0: <Intel 82801BA (D865) Pro/100 VE Ethernet> port 0xdf00-0xdf3f mem 
0xfe5ff000-0xfe5fffff irq 20 at device 8.0 on pci1
fxp0: Ethernet address 00:0e:a6:0a:51:36
miibus0: <MII bus> on fxp0
inphy0: <i82562ET 10/100 media interface> on miibus0
inphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
isab0: <PCI-ISA bridge> at device 31.0 on pci0
isa0: <ISA bus> on isab0
atapci0: <Intel ICH5 SATA150 controller> port 
0xfc00-0xfc0f,0-0x3,0-0x7,0-0x3,0-0x7 at device 31.2 on pci0
ata0: at 0x1f0 irq 14 on atapci0
ata0: [MPSAFE]
ata1: at 0x170 irq 15 on atapci0
ata1: [MPSAFE]
pci0: <serial bus, SMBus> at device 31.3 (no driver attached)
acpi_button0: <Power Button> on acpi0
atkbdc0: <Keyboard controller (i8042)> port 0x64,0x60 irq 1 on acpi0
atkbd0: <AT Keyboard> flags 0x1 irq 1 on atkbdc0
kbd0 at atkbd0
fdc0: <Enhanced floppy controller (i82077, NE72065 or clone)> port 
0x3f7,0x3f0-0x3f5 irq 6 drq 2 on acpi0
fdc0: FIFO enabled, 8 bytes threshold
npx0: [FAST]
npx0: <math processor> on motherboard
npx0: INT 16 interface
pmtimer0 on isa0
sc0: <System console> at flags 0x100 on isa0
sc0: VGA <16 virtual consoles, flags=0x300>
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
Timecounters tick every 10.000 msec
ipfw2 initialized, divert disabled, rule-based forwarding enabled, 
default to accept, logging disabled
ad0: 39205MB <Maxtor 6E040L0> [79656/16/63] at ata0-master UDMA100
ad2: 114473MB <ST3120026AS> [232581/16/63] at ata1-master UDMA100
ad3: 114473MB <ST3120026AS> [232581/16/63] at ata1-slave UDMA100
SMP: AP CPU #1 Launched!
Mounting root from ufs:/dev/ad0s1a