I'm still tweakin mine but from what i've noticed, the only thing that has ever set me back is trying to OC the memory by using the wrong divider!
You have DDR2-800 so to pervent from overclocking your memory, your Mem bus needs to not go over 400mhz. I'm assuming it's rated at 1.8v for your memory.
I've been able to run at my stock VID of 1.2375 all the way up to 3.130ghz before upping the vcore. I'm running 3.45 right now on just air and still tweaking. Temps max out during video encoding at 61C right now and may be able to reduce those with some more tweakin but that's install, not yours.
Keep your vcore at 1.2375 OR 1.2500v, set all your other voltage levels to AUTO for the time being and if you can change your GTL reference, change it to .61x as .63x is risky for this chip from what i've read.
Now, to ensure you are not OCing your memory, make sure it says either DDR-800(and nothing higher in the BIOS) or look for this divider number-
The best one i could think of is 9:8
DRAM:FSB = 9:8
this divider may not even exist but i'm going to show you why i chose this number.
Your current FSB is at 360mhz. Your memory is only rated to take 400mhz.
Given a 9:8 ratio, at 360mhz, you can have your memory at 403mhz which is a hair over spec, equals nothing special.
I bet you are OC-ing your memory.
Download CPU-z then click the memory tab and it will tell you what your ratio is. Post it here if u cant figure it out and we'll be able to see if you are OC'ing your memory or not.
this chip is actually more stable at lower voltages.
This chip is stock at 2.5 with VID of 1.2375, i'm at 3.45 and not even surpassed 1.3v yet on vcore.