AFAIK Letho's @ 1GHz is OPP5 = same as 600MHz on stock my ULV kernel voltages compared to stock: my <=250 is <0 stock (ultra low voltage) my 500 is ca. 0 stock (lower voltage) my 550/600 is 250 stock (low voltage) my 700/750/800 is <500 stock (low voltage) my 850 is 500 stock (normal voltage) my >=850 is 550 stock (overvoltage) does the ULV kernel work stable with 850/900/950/1000 for you?