It does exactly what it says it does - ignore nice load. Basically, if you leave that on 0, all processes count towards the up_threshold. If you set that to 1, renice'd processes don't count towards the up_threshold (can be bad or good depending on which app is misbehaving this time :P )

Leave it on 0.

EDIT: Saw the first post. Increase your voltages, simplify the steps. 125-1000 isn't recommended, try to do 250-1000 probably with steps in 250-500-750-1000, whatever voltage your phone needs, and if possible, SR on.