yank the vcore up a couple notches those chips get to a wall then you gotta make a jump in the vcore.

if your at 1.3v then go to 1.5 see what it does. if it goes lower it down a bit until you find the sweet spot.

ive had several cellies and they all do the same thing right around 3.7-3.8v

crank the vcore and see what she does.