These only mean that your Overclock is not stable, 4500 will be a bit hard to get on a 4670k under 1.3v you might want to try atleast 1.350v but thats not recommended. try setting your voltage at 1.250v @ 4.2 and see if its stable if it is try to lower the voltage by 0.005v untill you hit unstable or increase the multiplier to 4.3 and test again if not stable then keep increasing the voltage until you hit stable.
Good Luck!