Unknown p4-clockmod-capable CPU

Hello,

I tried to use cpufreq on my notebook. I couldn't get it run. "modprobe acpi_cpufreq" or any other try like "modprobe p4-clockmode" leads to the following error message:
/FATAL: Error inserting p4_clockmod (/lib/modules/2.6.24/kernel/arch/x86/kernel/cpu/cpufreq/p4-clockmod.ko):
No such device/

In dmesg I got the following message:
/p4-clockmod: Unknown p4-clockmod-capable CPU. Please send an e-mail to <[email protected]>
/
Here is more information about my CPU (It's an ACER 5220 Notebook). I hope this will help:
*-cpu
description: CPU
product: Intel(R) Celeron(R) CPU 530 @ 1.73GHz
vendor: Intel Corp.
physical id: 4
bus info: cpu@0
version: 6.6.1
slot: U2E1
size: 1730MHz
capacity: 1730MHz
width: 64 bits
clock: 133MHz
capabilities: fpu fpu_exception wp vme de pse tsc msr pae mce
cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss tm pbe nx x86-64 constant_tsc up arch_perfmon pebs bts pni monitor ds_cpl tm2 ssse3 cx16 xtpr lahf_lm
*-cache:0
description: L1 cache
physical id: 5
slot: L1 Cache
size: 64KB
capacity: 64KB
capabilities: asynchronous internal write-back
*-cache:1
description: L2 cache
physical id: 6
slot: L2 Cache
size: 1MB
capacity: 4MB
capabilities: burst internal write-back

Best regards,
Markus