So... I've been contacting several support communities the past couple of days to try to resolve the issue I'm having and I keep getting it's probably a hardware problem so I'll post here.
So far this has only occured when I play World of Warcraft. I just purchased a brand new machine through Ibuypower.com and it came to be through the mail and I will post the dxdiag info below. What happens is after anywhere from 1-2 hours of playing my monitor will suddenly go black and it'll come back as having "no signal" and the computer will either go to the choose a way to startup screen (safe mode, networking, normally, etc) or it just won't respond at all and I'll have to hold the power button to shut it down. I use CPUID HWMonitor to ensure temperatures aren't getting excessively high, and the highest I usually see is around 120F. I also use Who Crashed, but it's only been able to get a crash dump file once when this happened and it looks like this:
On Sat 11/12/2011 4:58:50 PM GMT your computer crashed
crash dump file: C:\Windows\Minidump\111211-14336-01.dmp
This was probably caused by the following module: ntoskrnl.exe (nt+0x4B16CC)
Bugcheck code: 0x124 (0x0, 0xFFFFFA8008257338, 0x0, 0x0)
file path: C:\Windows\system32\ntoskrnl.exe
product: Microsoft® Windows® Operating System
company: Microsoft Corporation
description: NT Kernel & System
Bug check description: This bug check indicates that a fatal hardware error has occurred. This bug check uses the error data that is provided by the Windows Hardware Error Architecture (WHEA).
This is likely to be caused by a hardware problem problem. This problem might be caused by a thermal issue.
The crash took place in the Windows kernel. Possibly this problem is caused by another driver which cannot be identified at this time.
Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.110622-1506)
BIOS: BIOS Date: 10/20/10 09:47:36 Ver: 08.00.10
Processor: AMD FX(tm)-6100 Six-Core Processor (6 CPUs), ~3.3GHz
Memory: 8192MB RAM
Available OS Memory: 8138MB RAM
Page File: 1621MB used, 14653MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled
DxDiag Version: 6.01.7601.17514 64bit Unicode
Card name: NVIDIA GeForce GTX 550 Ti
Chip type: GeForce GTX 550 Ti
The dxdiag file is extremely large so I didn't want to copy&paste it all, but if anyone wants to see more info I can give it. I'm thinking it's my power supply which is a 600 W PSU but I honestly have no idea how to find out if that's enough to run my setup. Any help at all will be greatly appreciated.