Comment 8 for bug 271973

For me:

saint@terminus:~$ sudo modprobe acpi_cpufreq

FATAL: Error inserting acpi_cpufreq (/lib/modules/2.6.27-7-generic/kernel/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.ko): Device or resource busy

was solved the problem.
It's interesting, that lsmod don't show the acpi_cpufreq module, but freq-scaling works now manual scaling works too.

saint@terminus:~$ lsmod | grep cpufreq

cpufreq_ondemand 16400 1
cpufreq_userspace 12420 0
cpufreq_powersave 10368 0
cpufreq_stats 14468 0
freq_table 13568 3 powernow_k8,cpufreq_ondemand,cpufreq_stats
cpufreq_conservative 16392 0

saint@terminus:~$