SMP interrupt wierdness in Linux 2.6.8.1 - Interrupt Load Balancing not working

Hello,

I've recently upgraded my SMP machine (2xPIII-500 on Asus P2B-D)
from Linux 2.4 to Linux 2.6.8.1 and now it seem's that the machine
only routes interrupts to one CPU. When loading the machine and
running top, I still only have seen 1 process in "Running" state
at the time. Should this be 2?

I have CONFIG_IRQBALANCE=y and of course CONFIG_SMP=y

lm@cleopatra:~$ cat /proc/interrupts
           CPU0       CPU1
  0:   36751142         16    IO-APIC-edge  timer
  1:          9          1    IO-APIC-edge  i8042
  2:          0          0          XT-PIC  cascade
  8:          3          0    IO-APIC-edge  rtc
 14:     273037          1    IO-APIC-edge  ide0
 15:       1189          0    IO-APIC-edge  ide1
 16:       8561          1   IO-APIC-level  sym53c8xx
 17:      40698          1   IO-APIC-level  sym53c8xx
 18:     110871          8   IO-APIC-level  ide2, ide3, ide4, ide5
 19:     219831          0   IO-APIC-level  eth0
NMI:          0          0
LOC:   36752415   36752416
ERR:          0
MIS:        245

When running 2.4 the interrupts was distributed between the two CPUs.

The CPU's are indentical:
lm@cleopatra:~$ cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 7
model name      : Pentium III (Katmai)
stepping        : 3
cpu MHz         : 501.328
cache size      : 512 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
mca cmov pat pse36 mmx fxsr sse
bogomips        : 989.18

processor       : 1
vendor_id       : GenuineIntel
cpu family      : 6
model           : 7
model name      : Pentium III (Katmai)
stepping        : 3
cpu MHz         : 501.328
cache size      : 512 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
mca cmov pat pse36 mmx fxsr sse
bogomips        : 999.42

Is there anyone out there who have an idea on where to start looking?

Best Regards,
/LM