idle process keeping cpu 150% busy in freebsd 9.1

[Kostas Oikonomou]

   Hello,
   I am new to FreeBSD. I just installed 9.1-RELEASE-p3 (comes with PC-BSD
   9.1) on an HP Pavilion s5100z.  The machine has a dual-core AMD Athlon
   7750 processor.
   What happens is that when I am doing nothing on the machine, one core
   is about 150%
   busy running the idle process:
   USER        PID  %CPU %MEM    VSZ   RSS TT  STAT STARTED    TIME
   COMMAND
   root         11 152.9  0.0      0    32 ??  RL    8:19AM 2:14.50 [idle]
   root          0   0.0  0.1      0  2672 ??  DLs   8:19AM 0:00.36
   [kernel]
   root          1   0.0  0.0   6276   416 ??  SLs   8:19AM 0:00.05
   /sbin/init --
   I have read [1]http://forums.freebsd.org/showthread.php?t=38757, which
   seems to be relevant, and I tried
   sysctl -w kern.eventtimer.timer=<various choices>
   as they suggest, but to no avail.
   One more piece of information: the only possible problem I see when the
   machine boots is the following in dmesg:
   ...
   acpi0: <HPQOEM SLIC-CPC> on motherboard
   acpi0: Power Button (fixed)
   ACPI Error: Field [ASSM] at 524320 exceeds Buffer [BUF0] size 880
   (bits) (20110527/dsopcode-254)
   ACPI Error: Method parse/execution failed [\\_SB_.MEM_._CRS] (Node
   0xfffffe0003cfc380), AE_AML_BUFFER_LIMIT (20110527/psparse-560)
   ACPI Error: Method execution failed [\\_SB_.MEM_._CRS] (Node
   0xfffffe0003cfc380), AE_AML_BUFFER_LIMIT (20110527/uteval-113)
   can't fetch resources for \\_SB_.MEM_ - AE_AML_BUFFER_LIMIT
   cpu0: <ACPI CPU> on acpi0
   cpu1: <ACPI CPU> on acpi0
   ...
   Any help would be greatly appreciated.
                               Kostas

References

   1. http://forums.freebsd.org/showthread.php?t=38757