FreeBSD hangs on Dell PE2850 needs usb keyboard to revive

[Sec Updates Account]

Hi ,
I am facing a strange but critical issue.
I have a FreeBSD 6.2 server ,this server runs on PE2850 with 4G ram
and Dual Xeon's . Every once in a while the server will just hang , no
network connectivity or anything else. if i plugin a USB keyboard ,
the server will come back to life as if nothing happend. the server
works fine and with out a problem until next time.
I tried diabeling ACPI but that did not change a thing.

I have enbaled all *.* to all.log and been digging through logs to
find a solution with no luck.

at this point I am open to ANY suggestion .


my dmesg output after keyboard inserted :
ukbd0: DELL DELL USB Keyboard, rev 1.10/1.05, addr 2, iclass 3/1
kbd2 at ukbd0

my hardware :
Copyright (c) 1992-2007 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
        The Regents of the University of California. All rights reserved.
FreeBSD is a registered trademark of The FreeBSD Foundation.
FreeBSD 6.2-STABLE #0: Sun Sep  2 14:49:17 GMT 2007
    toor at ed1srv01.etadirect.net:/usr/obj/usr/src/sys/CARP
WARNING: debug.mpsafenet forced to 0 as ipsec requires Giant
WARNING: MPSAFE network stack disabled, expect reduced performance.
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel(R) Xeon(TM) CPU 2.80GHz (2783.82-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>
  Features2=0x4400<CNTX-ID,<b14>>
  Logical CPUs per core: 2
real memory  = 4026400768 (3839 MB)
avail memory = 3942158336 (3759 MB)
MPTable: <DELL     PE 0121     >
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
 cpu0 (BSP): APIC ID:  0
 cpu1 (AP): APIC ID:  6
ioapic0: Changing APIC ID to 8
ioapic0: Assuming intbase of 0
ioapic1: Changing APIC ID to 9
ioapic1: Assuming intbase of 16
ioapic2: Changing APIC ID to 10
ioapic2: Assuming intbase of 32
ioapic0 <Version 1.1> irqs 0-15 on motherboard
ioapic1 <Version 1.1> irqs 16-31 on motherboard
ioapic2 <Version 1.1> irqs 32-47 on motherboard
kbd1 at kbdmux0
ath_hal: 0.9.20.3 (AR5210, AR5211, AR5212, RF5111, RF5112, RF2413, RF5413)
cpu0 on motherboard
cpu1 on motherboard
pcib0: <MPTable Host-PCI bridge> pcibus 0 on motherboard
pci0: <PCI bus> on pcib0
pcib0: unable to route slot 15 INTA
pci0: <unknown> at device 4.0 (no driver attached)
pci0: <unknown> at device 4.1 (no driver attached)
pci0: <unknown> at device 4.2 (no driver attached)
pci0: <display, VGA> at device 14.0 (no driver attached)
atapci0: <ServerWorks CSB5 UDMA100 controller> port
0x1f0-0x1f7,0x3f6,0x170-0x177,0x376,0x8b0-0x8bf at device 15.1 on pci0
ata0: <ATA channel 0> on atapci0
ata1: <ATA channel 1> on atapci0
ohci0: <OHCI (generic) USB controller> mem 0xfe100000-0xfe100fff irq 5
at device 15.2 on pci0
ohci0: [GIANT-LOCKED]
usb0: OHCI version 1.0, legacy support
usb0: <OHCI (generic) USB controller> on ohci0
usb0: USB revision 1.0
uhub0: (0x1166) OHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 4 ports with 4 removable, self powered
isab0: <PCI-ISA bridge> at device 15.3 on pci0
isa0: <ISA bus> on isab0
pcib3: <MPTable Host-PCI bridge> pcibus 3 on motherboard
pci3: <PCI bus> on pcib3
bge0: <Broadcom BCM5703 A2, ASIC rev. 0x1002> mem
0xfcf10000-0xfcf1ffff irq 28 at device 6.0 on pci3
miibus0: <MII bus> on bge0
brgphy0: <BCM5703 10/100/1000baseTX PHY> on miibus0
brgphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT,
1000baseT-FDX, auto
bge0: Ethernet address: 00:11:43:d6:d0:e1
bge0: [GIANT-LOCKED]
bge1: <Broadcom BCM5703 A2, ASIC rev. 0x1002> mem
0xfcf00000-0xfcf0ffff irq 29 at device 8.0 on pci3
miibus1: <MII bus> on bge1
brgphy1: <BCM5703 10/100/1000baseTX PHY> on miibus1
brgphy1:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT,
1000baseT-FDX, auto
bge1: Ethernet address: 00:11:43:d6:d0:e2
bge1: [GIANT-LOCKED]
pcib4: <MPTable Host-PCI bridge> pcibus 4 on motherboard
pci4: <PCI bus> on pcib4
pcib5: <MPTable PCI-PCI bridge> at device 8.0 on pci4
pci5: <PCI bus> on pcib5
aac0: <Dell PERC 3/Di> mem 0xf0000000-0xf7ffffff irq 30 at device 8.1 on pci4
aac0: [FAST]
aac0: Adaptec Raid Controller 2.0.0-1
pcib1: <MPTable Host-PCI bridge> pcibus 1 on motherboard
pci1: <PCI bus> on pcib1
pcib2: <MPTable Host-PCI bridge> pcibus 2 on motherboard
pci2: <PCI bus> on pcib2
pmtimer0 on isa0
orm0: <ISA Option ROMs> at iomem
0xc0000-0xc7fff,0xc8000-0xcbfff,0xec000-0xeffff on isa0
atkbdc0: <Keyboard controller (i8042)> at port 0x60,0x64 on isa0
atkbd0: <AT Keyboard> irq 1 on atkbdc0
kbd0 at atkbd0
atkbd0: [GIANT-LOCKED]
fdc0: <Enhanced floppy controller> at port 0x3f0-0x3f5,0x3f7 irq 6 drq 2 on isa0
fdc0: [FAST]
fd0: <1440-KB 3.5" drive> on fdc0 drive 0
ppc0: parallel port not found.
sc0: <System console> at flags 0x100 on isa0
sc0: VGA <16 virtual consoles, flags=0x300>
sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0
sio0: type 16550A
sio1 at port 0x2f8-0x2ff irq 3 on isa0
sio1: type 16550A
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
unknown: <PNP0c02> can't assign resources (memory)
unknown: <PNP0501> can't assign resources (port)
unknown: <PNP0501> can't assign resources (port)
unknown: <PNP0700> can't assign resources (port)
unknown: <PNP0303> can't assign resources (port)
unknown: <PNP0c01> can't assign resources (port)
ukbd0: DELL DELL USB Keyboard, rev 1.10/1.05, addr 2, iclass 3/1
kbd2 at ukbd0
Timecounters tick every 1.000 msec
IPsec: Initialized Security Association Processing.
acd0: CDROM <TEAC CD-ROM CD-224E/K.9A> at ata0-master UDMA33
aacd0: <RAID 5> on aac0
aacd0: 69425MB (142182656 sectors)
SMP: AP CPU #1 Launched!
Trying to mount root from ufs:/dev/aacd0s1a
Accounting enabled