You're gonna want to really check the temps thoroughly with that thing, I've found from past experience that thermal pads tend to really suck compared to decent thermal paste, more so if it's not covering the entire surface of the CPU (is it?)
Also, what sort of cooling do you have, is it overheating?
My rig was getting a little warm recently because dust had accumulated in the rad for my H50 - bear in mind this is only eight weeks worth, in a relatively clean flat:
Lol at "mouse surface"
Isn't exactly going to be necessary in diagnosing this...
First, have you checked that overclock is stable?
Run OCCT for an hour. 1.288v @ 4.2Ghz isn't something I'd bet on being stable.
I would personally advise trying to get it a little more stable than this (ie, it should be able to run linpack tests like linX on maximum for a decent number of runs and get no errors...)
Otherwise you're not really stable.
Sweet Jesus you got ripped off!
Also, you need to be using something other than AvP to test stability with. When that Configuration can stand up to an hour or two of OCCT linpack at maximum memory usage then you can call it stable.
It's not "on the verge of high" - it's a voltage that will probably cause degredation of the chip - shouldn't take too long either.
cadaveca even demonstrated this :p
1.5 is considered relatively safe, wouldn't go much over that...
This is probably the best OC I've seen on a graphics card using the reference cooler (although it loses stability under full load at >~1015Mhz or over 1.3v, possibly due to restrictions in the amount of power it can draw from two 6-pin sockets and the motherboard).
I advised a friend to get one...