Only one CPU is brought up. In dmesg it says: SMP motherboard not detected. 

Both cpu's where found when booting from the installation CD, but after 
firt reboot and subsequent boots it reports "SMP motherboard not detected". 

First lines of dmesg

Bootdata ok (command line is root=/dev/sda6 vga=0x31a selinux=0    resume=/dev/s
da8  splash=silent)
Linux version 2.6.16-rc1-git3-7-smp (geeko@buildhost) (gcc version 4.1.0 2006012
3 (prerelease) (SUSE Linux)) #1 SMP Mon Jan 30 21:52:12 UTC 2006
BIOS-provided physical RAM map:
 BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
 BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
 BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved)
 BIOS-e820: 0000000000100000 - 000000003ffb0000 (usable)
 BIOS-e820: 000000003ffb0000 - 000000003ffbe000 (ACPI data)
 BIOS-e820: 000000003ffbe000 - 000000003ffe0000 (ACPI NVS)
 BIOS-e820: 000000003ffe0000 - 0000000040000000 (reserved)
 BIOS-e820: 00000000ff780000 - 0000000100000000 (reserved)
ACPI: RSDP (v002 ACPIAM                                ) @ 0x00000000000fb1e0
ACPI: XSDT (v001 A M I  OEMXSDT  0x11000504 MSFT 0x00000097) @ 0x000000003ffb010
0
ACPI: FADT (v003 A M I  OEMFACP  0x11000504 MSFT 0x00000097) @ 0x000000003ffb029
0
ACPI: MCFG (v001 A M I  OEMMCFG  0x11000504 MSFT 0x00000097) @ 0x000000003ffb03f
0
ACPI: OEMB (v001 A M I  AMI_OEM  0x11000504 MSFT 0x00000097) @ 0x000000003ffbe04
0
ACPI: DSDT (v001  A0387 A0387001 0x00000001 INTL 0x02002026) @ 0x000000000000000

Scanning NUMA topology in Northbridge 24
Number of nodes 1
Node 0 MemBase 0000000000000000 Limit 000000003ffb0000
NUMA: Using 63 for the hash shift.
Using node hash shift of 63
Bootmem setup node 0 0000000000000000-000000003ffb0000
No mptable found.
On node 0 totalpages: 256952
  DMA zone: 3014 pages, LIFO batch:0
  DMA32 zone: 253938 pages, LIFO batch:31
  Normal zone: 0 pages, LIFO batch:0
  HighMem zone: 0 pages, LIFO batch:0
ATI board detected. Using APIC timer.
ACPI: PM-Timer IO Port: 0x4008
Allocating PCI resources starting at 50000000 (gap: 40000000:bf780000)
Checking aperture...
CPU 0: aperture @ 3a04000000 size 32 MB
Aperture from northbridge cpu 0 too small (32 MB)
No AGP bridge found
SMP: Allowing 0 CPUs, 0 hotplug CPUs
Built 1 zonelists

Kernel command line: root=/dev/sda6 vga=0x31a selinux=0    resume=/dev/sda8  spl
ash=silent
bootsplash: silent mode.
Initializing CPU#0
PID hash table entries: 4096 (order: 12, 131072 bytes)
time.c: Using 3.579545 MHz PM timer.
time.c: Detected 1804.155 MHz processor.
Console: colour dummy device 80x25
Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes)
Inode-cache hash table entries: 65536 (order: 7, 524288 bytes)
PCI-DMA: Disabling IOMMU.
Memory: 1017248k/1048256k available (1884k kernel code, 30620k reserved, 880k da
ta, 184k init)
Calibrating delay using timer specific routine.. 3615.00 BogoMIPS (lpj=7230019)
Security Framework v1.0.0 initialized
Mount-cache hash table entries: 256
CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line)
CPU: L2 Cache: 1024K (64 bytes/line)
CPU 0(2) -> Node 0 -> Core 0
mtrr: v2.0 (20020519)
checking if image is initramfs... it is

Freeing initrd memory: 2664k freed
 not found!
    ACPI-0311: *** Error: ns_search_and_enter: Bad character in ACPI Name: 43005
350
    ACPI-0292: *** Error: Looking up [0x43005350] (NON-ASCII)
 in namespace, AE_BAD_CHARACTER
    ACPI-0287: *** Warning: During name lookup/catalog, AE_BAD_CHARACTER
    ACPI-0115: *** Error: acpi_load_tables: Could not load namespace: AE_BAD_CHA
RACTER
    ACPI-0123: *** Error: acpi_load_tables: Could not load tables: AE_BAD_CHARAC
TER
ACPI: Unable to load the System Description Tables
weird, boot CPU (#0) not listed by the BIOS.
SMP motherboard not detected.
Using local APIC timer interrupts.
Detected 12.528 MHz APIC timer.
timer: PIT interrupt stopped.
spurious 8259A interrupt: IRQ7.
testing NMI watchdog ... OK.
SMP disabled
Brought up 1 CPUs