Issues with ondemand governor on overclocked CPU

Hi,

I am using a Core2 Quad (Q9650) on a Gigabyte GA-EP45-DS4 board. The default CPU specs look like this:
* FSB: 333MHz,
* Multiplier: 6-9

without overclocking frequency scaling with acpi-cpufreq works pretty well - it either uses a 6x multiplier (2 GHz) or a 9x multiplier (3 GHz).

After setting the FSB to 400MHz and limiting the multiplier to 6-8 in the BIOS (3,2 GHz), frequency scaling with the ondemand governor does not work any more. The actual frequency information is still correct:

# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies 
3200000 2400000

However the ondemand governor does not do any upscaling any more - the CPU is stuck at 2,4 GHz. It is still possible to use the maximum frequency by setting "scaling_min_freq" to "3200000" (or probably by using the performance governor).

Is this expected? Could this be a bug? Without limiting the multiplier (leaving the default 6/9) ondemand scaling also works as usual (2,4 GHz/3,6 GHz).

Kernel version: 2.6-git

Regards,
Daniel