cpufreq limits overridden?

[Vermind]

Hi,
I have an Asus UX31 ultrabook with a core i7 4-core processor, running Ubuntu 12.04.
It overheats when playing Zero-K ( http://zero-k.info/ , a Spring engine game ). The overheat causes an immediate shutdown if I do not stop the game before that.
I am trying to workaround the overheat by setting cpufreq limits like this:

cpufreq-set -r --max 1.20GHz -g ondemand

The 1.2 GHz limit holds for some 5-10 minutes when starting the game, but after that the 4 cores just go up to 1.8 GHz without permission. I can see this with

sudo cpufreq-info | grep current

The (asserted by call to hardware) numbers climb to 1.8 GHz while the limits stay the same. Also, without sudo I only get values within the limits, since the user cannot query the hardware.

Any idea how I can keep the CPU from going above the cpufreq limits or workaround the overheat in another way?

P.S. I am using this GNOME Shell extension to see that the CPU overheats: https://github.com/xtranophilist/gno...pu-temperature

Thanks,