Passive cooling problem with Athlon CPU

[Mike Clarke]

I'm running 6.3STABLE with an AMD 4850e Athlon X2 and occasionally get 
the following message on the console:

acpi_tz0: failed to set new freq, disabling passive cooling

I also see the following 2 messages immediately after devd starts every 
time I boot (and which don't appear in any log file):

hw.acpi.cpu.cx_lowest: C1
sysctl: hw.acpi.cpu.cx_lowest: Invalid argument

Should I be concerned about this and, if so, what should I do?

The CPU info from dmesg:

Copyright (c) 1992-2008 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
        The Regents of the University of California. All rights 
reserved.
FreeBSD is a registered trademark of The FreeBSD Foundation.
FreeBSD 6.3-STABLE #0: Mon Jun 30 13:32:39 BST 2008
    root at curlew.lan:/usr/obj/usr/src/sys/SMP
ACPI APIC Table: <Nvidia NVDAACPI>
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: AMD Processor model unknown (2410.99-MHz 686-class CPU)
  Origin = "AuthenticAMD"  Id = 0x60fb2  Stepping = 2
  
Features=0x178bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PS
E36,CLFLUSH,MMX,FXSR,SSE,SSE2,HTT>
  Features2=0x2001<SSE3,CX16>
  AMD Features=0xea500800<SYSCALL,NX,MMX+,FFXSR,RDTSCP,LM,3DNow!
+,3DNow!>
  AMD Features2=0x11f<LAHF,CMP,SVM,ExtAPIC,CR8,Prefetch>
  Cores per package: 2
real memory  = 2080309248 (1983 MB)
avail memory = 2017738752 (1924 MB)
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
 cpu0 (BSP): APIC ID:  0
 cpu1 (AP): APIC ID:  1
ioapic0: Changing APIC ID to 2
ioapic0 <Version 1.1> irqs 0-23 on motherboard

... and output from grep acpi /var/run/dmesg.boot

acpi0: <Nvidia NVDAACPI> on motherboard
acpi0: Power Button (fixed)
acpi_timer0: <24-bit timer at 3.579545MHz> port 0x1008-0x100b on acpi0
acpi_hpet0: <High Precision Event Timer> iomem 0xfeff0000-0xfeff03ff on 
acpi0
device_attach: acpi_hpet0 attach returned 12
cpu0: <ACPI CPU> on acpi0
cpu1: <ACPI CPU> on acpi0
acpi_button0: <Power Button> on acpi0
pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0
acpi_tz0: <Thermal Zone> on acpi0
fdc0: <floppy drive controller> port 0x3f0-0x3f5,0x3f7 irq 6 drq 2 on 
acpi0
sio0: <16550A-compatible COM port> port 0x3f8-0x3ff irq 4 flags 0x10 on 
acpi0
sio1: <Generic IRDA-compatible device> port 0x2f8-0x2ff irq 3 on acpi0
ppc0: <Standard parallel printer port> port 0x378-0x37f irq 7 on acpi0
atkbdc0: <Keyboard controller (i8042)> port 0x60,0x64 irq 1 on acpi0
acpi_hpet0: <High Precision Event Timer> iomem 0xfeff0000-0xfeff03ff on 
acpi0
device_attach: acpi_hpet0 attach returned 12

-- 
Mike Clarke