I7-860, 1-2 core run hotter than other 2?

Just moved to the i7-860 from a C2Q Q6600. I installed an AC Freezer 7 Pro Rev.2. The odd thing is that unlike my Q6600 (which all 4 cores idled together no more than 3C difference) I have some strange variance with my 860.

Typical idle temps:

Core0: 33C
Core1: 33C
Core2: 37C
Core3: 42C

I got these rough numbers after watching a temp chart in speedfan 4.40.

I even removed the cooler/heatsink, cleaned it and the CPU, reapplied thermal paste (arctic silver ceramic) and ensured ample coverage and still produced this imbalance. I don't have any tasks running, I can see my cores' activity and they all flicker around 0-2% utilization. So I really don't get what is up. Unfortunately, I haven't done a test to see if this variance occurs when fully loaded (I'll use prime95 to test). I am currently at work and had to ask this, been in the back of my head. Got a great case for cooling too, so not sure what's going on. Is this because of turbo and one or two of the cores is clocked higher? But I thought when idle that obivously wouldn't happen, Speedstep would be on (which I have confirmed with CPUZ and show 1.2 GHZ clock when idle) and there would be no imbalance.

Comp specs if needed:

Lian Li PC-P50 case
Win 7 Home Premium
Asus P7P55D-E PRO
i7-860-stock freq. (Speedstep and turbo enabled in BIOS)
4GB Corsair DDR3 1333 RAM (2x2GB)
Asus 5870 1GB V2
WD-1TB, 250GB, 160GB

Don't know what else you would need to know, appreciate any help, thanks.