Adding "nosmp apm=force noapic api=off pci=noacpi" after a reboot of system 
appeared to work on first inspection.   Some time after reboot there are more 
interrupts and a write to /var/log/messages.   Hard on a disk to say the 
least.
What we see is:
Jun 25 09:31:47 engr01 kernel: spurious APIC interrupt on CPU#0, should never 
happen.
Jun 25 09:32:55 engr01 kernel: spurious APIC interrupt on CPU#0, should never 
happen.
Jun 25 09:34:37 engr01 kernel: spurious APIC interrupt on CPU#0, should never 
happen.
Jun 25 09:36:03 engr01 kernel: spurious APIC interrupt on CPU#0, should never 
happen.
Jun 25 09:41:35 engr01 kernel: spurious APIC interrupt on CPU#0, should never 
happen.
Jun 25 09:43:42 engr01 kernel: spurious APIC interrupt on CPU#0, should never 
happen.
Jun 25 09:45:37 engr01 last message repeated 2 times
Jun 25 09:46:56 engr01 last message repeated 2 times
Jun 25 09:48:12 engr01 kernel: spurious APIC interrupt on CPU#0, should never 
happen.
Jun 25 09:50:09 engr01 kernel: spurious APIC interrupt on CPU#0, should never 
happen.
Jun 25 09:52:07 engr01 last message repeated 2 times
Jun 25 09:54:36 engr01 kernel: spurious APIC interrupt on CPU#0, should never 
happen.
Jun 25 10:01:00 engr01 last message repeated 4 times
Jun 25 10:02:47 engr01 last message repeated 3 times
Jun 25 10:04:53 engr01 last message repeated 2 times

There does not seem to be much on the net that offers any advice or ???

Need to solve this problem before I have another disk to swap out.

It is unique to a single core processor installation, as we have looked for 
this same activity on several boxes with multi core processor and it doesn't 
happen.

Larry Linder