Strange temps in different programs and failed overclocking

right so here's my problem, I ahve intels extreme overclocking utility and asus ai suite II (comes with my motherboard) the monitored temps on my ai suite are generally 10 degrees C lower than intel's overclocking utility, why is this? 

And problem number 2, about once in every 20 boots my computer comes up with overclocking failed, press f1. when my overclocking is completely stable (monitored for 24 hours, definately stable for that long) any idea why this is?

Additional information:

i5 3570k overclocked @ 4.2 ghz

stock cooler (keeps my core, when at 100%, in the high 60's and low 70's, might be becuase my room is so cold)

asus p8z77-v motherboard

WHY ARE YOU USING THE STOCK COOLER??????? You need an aftermarket cooler to overclock....

i dont see why not, it overclocks to 4.2ghz on stock dont need an aftermarket unless I want to go higher

You can overclock on a stock cooler.

The asus temp doesnt factor in ambient, the other ones do. So if your room is 18 degress plus what the mobo says, it should be close to what the software is saying. I also have a ROG board, your OC is not stable, it only says that if it failed to boot or crashed so that means it isnt stable. 

hmmm, i had it running 24 hours straight and it was stable

Prime95 stable with WHEA errors or with out WHEA errors? Also make sure you use p95 v27.7. An I am running satock cooler @4.1ghz too. Cold basement temps help. I have to agree that it sounds like your OC is not stable. Since your temps are low. Up you volts a tiny bit. what volts are you getting under max load? I am running core volts 1.136v-1.144v max load. Reason I ask bout volts is I know upp[ing the volts helps get rid of the WHEA errors. So its seems to me with IB too low of volts make it very unstable.

You can always fold with it. Folding will let you know how stable it truley is. I've seen p95 12hr-24hr stable OC fail when it comes to folding.