You can try using my patch - http://my.arava.co.il/~matan/770/n900/freqs.diff It reduces the voltage for the frequencies 550 and 600 to OPP3 level (the one used for 500 in Nokia's kernel, and uses OPP4 level for 720-1000 (the same level as originally used for 550). Highest level (OPP5) which is used for 600 in Nokia's kernel, is not used at all in my patch. Of course, the result will be lower maximum frequency in some CPUs, but my is stable at 1000MHz even at this lower voltage.