Windows 7 black screen and forced shutdown

So three times now, since the september launch, I have a recurring problem. During play the screen will just cut out and go black, and my tv will say no signal after a few seconds, then after a few more seconds it cuts back in and my computer is shutting down programs and then it turns off, almost like a normal shutdown. Now it didnt happen until like 4 months after launch the 1st time. I couldnt find a solution so i reinstalled my os and game and it seemed to do the trick. Then a few months later it did it again, still couldnt figure it so i reinstalled the os and game and again it worked. Now it just did it again. My computer is more than capable of running XIV, I built it with XIV in mind, and scored a 4400 on the benchmark.

Specs:
3.2 quad core processor
radeon hd5750 graphics card
4gb ddr5 ram
windows 7 64bit
850w power supply

Now this only happens when running final fantasy xiv, everything else will run fine when the problem starts to happen, but 14 will make my screen cut out and force my comp to shut down. Ive ruled out power supply becuase its 850w, which is plenty. Its not an overheat issue becuase when i turn on my comp after it shuts down it says everything is around 60c and ive physically checked components for heat after a shut down.

Does anyone know what the problem is or is anyone having the same problem?

Is it every time you start up FFXIV, and how long are you in the game before this happens? Do you get past the character select screen? Do you have dual monitors? What is going on, on that second monitor, if you have one?
What video drivers are you using?

Needs more information.(It sounds like an issue I had, and resolved, but I'll wait for more information to pop my issue out there.)

Sounds similar to the issue I had when I went to using a wireless keyboard and mouse. For some reason my computer would go to sleep when I was playing FFXIV using Wireless devices. I even disabled the option for my computer to go to sleep and it still did it. So I am using a corded mouse and keyboard and haven't had the problem since. Not too sure what to make of it. If you are having the same issue I'd recommned using corded devices for a bit to see if the problem still happens.

Wow 4 gigs of DDR5 Ram? ;-)