Serial Console activation causes system freeze (8.2-Stable)

[BBLister]

Greetings,


Ι have followed the guide about setting up the serial console:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/ppp-and-slip.html

Ι have done this many times with no problems to other servers.

For the first time I have a very strange problem in this particular server: 
After seeing some kernel messages, Ι see garbage characters, the machine hangs completely and only a hard reset can be done. 
The garbage characters appear just before the uart initilization.

The last messages that I can see in the serial console:


....
atapci2: <Intel 6300ESB SATA150 controller> port 0xa800-0xa807,0xa480-0xa483,0xa400-0xa407,0xa080-0xa083,0xa000-0xa00f irq 18 at device 31.2 on pci0
atapci2: [ITHREAD]
ata5: <ATA channel 0> on atapci2
ata5: [ITHREAD]
ata6: <ATA channel 1> on atapci2
ata6: [ITHREAD]
pci0: <serial bus, SMBus> at device 31.3 (no driver attached)
acpi_button0: <Power Button> on acpi0
atrtc0: <AT realtime clock> port 0x70-0x71 irq 8 on acpi0
atkbdc0: <Keyboard controller (i8042)> port 0x60,0x64 irq 1 on acpi0
atkbd0: <AT Keyboard> irq 1 on atkbdc0
kbd0 at atkbd0
atkbd0: [GIANT-LOCKED]
atkbd0: [ITHREAD]
���������������������� ��?����� ���� ��?� ��?� ��?M����/���~��������/�����~���M����/�����~���M�������������{>�{>�?<����'�����'����?<�����������?u��u��������~^D

==> at this point the whole machine freezes! (notice that
in the previous case the kernel hangs before any getty is initialized)


If I disable the serial console in loader.conf and boot.config then I have normal boot:

....
atkbd0: [GIANT-LOCKED]
atkbd0: [ITHREAD]
uart0: <16550 or compatible> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0
uart0: [FILTER]
uart1: <16550 or compatible> port 0x2f8-0x2ff irq 3 on acpi0
uart1: [FILTER]
....


Details:
FreeBSD unix3.icte.uowm.gr 8.2-STABLE FreeBSD 8.2-STABLE #1: Mon Jan 16 15:54:50 EET 2012     root at unix_2:/usr/obj/usr/src/sys/unix  amd64

CPU: Intel(R) Xeon(TM) CPU 3.40GHz (3391.51-MHz K8-class CPU)
  Origin = "GenuineIntel"  Id = 0xf4a  Family = f  Model = 4  Stepping = 10
  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=0x649d<SSE3,DTES64,MON,DS_CPL,EST,CNXT-ID,CX16,xTPR>
  AMD Features=0x20100800<SYSCALL,NX,LM>
  AMD Features2=0x1<LAHF>
  TSC: P-state invariant
real memory  = 8589934592 (8192 MB)
avail memory = 8243875840 (7861 MB)
ACPI APIC Table: <A M I  OEMAPIC >
FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs
FreeBSD/SMP: 2 package(s) x 1 core(s) x 2 HTT threads



Please help me...




Regards,


BB