The ONLY crashes I see on a regular basis happen on the one machine that has 6 cores instead of 4, and has a GTX 570 instead of a Galaxy 670. All other specs the same (32GB ram, Velociraptor 10k scratch disks, raid 5 backup, i7 processor, P9X79 Deluxe MB, etc...). So I was thinking it could potentially be a video driver issue.

The first time I installed it, I had issued. A week later they released a new firmware, everything seemed to go stable (last Fall). Then they've released several updates... The 2nd to last one crippled rendering. I got green screens on render, all sorts of glitches. The latest firmware update seemed to fix a few things, but I am still getting 1/4 renders as a fail. The way mine fails is the render starts, counter begins, but I never see frames moving and it never makes any percentage progress. Just hangs, and I have to force close.

If I disabled GPU the render issues disappear.

How many ram sticks are you using? 8x4GB or 4x8GB? If you 8x4 try using only 4x4 and test again. There are issues on X79 boards with all ram slots occupied. It could also be a ram timing issue or a faulty/slightly out of spec ram stick. I tested my system with Cinebench 11.5 to check for stability.

I will run Cinebench tonight. I am using 4x8GB sticks. All other workstations are exactly the same specs, so it can't be the RAM/MB. The ONLY difference between my other workstations and this one, is the 6core i7 vs 4core i7, and the GPU on the others is the Galaxy GTX 670.

See current specs... (note Adobe CS6 loves these machines. Only Vegas is buggy, as usual.)

Fractal XL R2 Case (TONS of HD bays open)
MB - Asus P9X79 Deluxe
Processor - Intel Core i7-3930K + Intel Liquid cooling
Ram - 32GB
GPU - Galaxy GTX 670
120GB SSD for main OS/software
(2) two - 10k WD Velociraptor drives for scratch disks (video editing)
Rocketraid 220 PCIe Card --> G-Speed eS (6TB, RAID5)

4x8 checked. What speed are you running at? 1600, 1866, 2133 and voltage? I run a specified 2133 ram at 1600 on my i7-3930K and that is stable as a rock and not any slower according to Cinebench. I also run it at 1.5V just to be safe. System side we are almost identical but I use an Intel MB and ASUS GPU and SSD's only aside from a Raid 1 Storage array. Vegas has always been stable for me and I don't see the problems many others have with it.

Edit:
Check all your drive cables and connectors for correct fit. I waisted 3 days on a not latched SATA III connector that caused random render errors and BSOD.

Can't run Cinebench! It wont let me accept or decline the agreement! Any other suggestions? (Will check specs shortly, know all cables are solid btw)

Hmmm.... I had no problem with it. I downloaded mine from Guru3D.com
http://downloads.guru3d.com/CineBENCH-11.5-download-2475.html

For some reason had to open 32bit version, hit accept, then run it.

Results show that my rig rocks. No issues, no instability, top of its class on the rankings. Do you know of any stress-test software for me to run?

You can try PassMark but it is a benchmark utility. Are you still having issues with the 6 core PC?

Yes. Crashes when I do things like 'hit play'. =) Vegas11 crashes on the other machines too, just not as frequently. Concerned that it might be the GTX 570 with newer drivers. Going to try to rollback later today. This is the only program that causes issues. No Wacom tablet btw. Others reported that as an issue. I also made sure that this computer did not have any of my Intensity Pro capture cards or anything like that.