PC Freezing?

[SubFocus]

Hello All,

Put together a new build. It's been running fine all yesterday, under a lot of stress (bfbc2, vietnam, wow, bunch of games i played yesterday without problems) yet today the PC seems to be freezing. I'll lose control of the mouse and nothing else responds then i need to restart to get back on. It will then freeze again short after. I checked the temps of the hardware manually, the RAM seems quite hot but what's really hot is this "V8" plasting cover thing on the motherboard. It sits directly under my GPU. My specs are as follows:

Asus GeForce GTX 580 Matrix Platinum 1536MB GDDR5
Intel Core i5-2500K 3.30GHz (Sandybridge)
Asrock Z68 Extreme4 Gen3 Intel Z68 (Socket 1155) DDR3 Motherboard
OCZ Z-Series 850W '80 Plus Gold' Modular Power Supply
Cooler Master CM-690 II Nvidia Edition Advanced Dominator Case
Crucial RealSSD M4 64GB 2.5" SATA 6Gb/s Solid State Hard Drive
Corsair XMS3 8GB (2x4GB) DDR3 PC3-12800C9 1600MHz Dual Channel

I haven't overclocked anything. Here are the temps:

And the V8 i'm talking about:

Any ideas?

edit; the v8 part is getting VERY hot. PC was on for 5 minutes and i couldn't comfortably hold my finger on it for longer than 3 seconds, is this normal?

 

[stulid]

Is the system overclocked? try the latest BIOS for the board and the 009 SSD firmware update.

 

[Emphacy]

The southbridge shouldn't get particularly hot. These days it's the NB which handles the PCI-E configuration, the SB should be cold enough to keep your finger on.

I'd say run a Memtest 86+ as well to make sure your memory isn't generating any errors.
Check your BIOS to ensure your memory isn't running at some kind of silly speed and that it's running normal.

Also, since it's just been built, I'd say check for short circuits behind the board, anything like this can cause an overvoltage increasing heat.