Well, I've asked about this issue in a couple different tech support forums and nobody seems to know anything, so I guess I'll throw it up here.

Three or four days ago I re-installed Metro 2033, found that I was missing NVIDIA's Physx .dll (I have 2x Radeon 6850's). So I went and downloaded the Physx driver package, loaded up Metro, and a few hours into playing something happened that's never happened to me before - my monitor lost signal for no apparent reason, despite the fact that my PC was still running. The only thing I could do was a hard reset.

So I figured it's a driver incompatibility issue, deleted all NVIDIA drivers with Driver Sweeper, updated my Radeon drivers, and un-installed Metro, however my monitor is still losing signal when I try to play Crysis 2 - anywhere from 1 minute to 30 minutes in. The reason I'm bringing this up here is that it only seems to happen when I'm playing Crysis 2! I've been able to run Crysis, Warhead, and Borderlands just fine. Also furmark. Everything seems stable except Crysis 2. I finished re-installing C2 and loaded up a fresh profile - deleted all my old saves and everything - but before I was even out of the damned submarine my monitor cuts out again. So my question is... WTF?

System Specs:
Win7 Home Prem. 64bit
Intel Core 2 Quad Q9300 @ 3ghz (OC)
2x Radeon 6850's (been using only 1 for C2 due to the flickering issues)
8GBs DDR3 RAM
Gigabyte GA-EP45T-USB3P Mobo,
etc.

Crysis 2 Steam or Disc ver? Also have you tried going to the 'root directory', right clicking on the main .exe file that runs the game, go to properties and experiment with different compatibility modes ie. Windows XP SP3 mode. Also ensure you are always running as an administrator too. If yes to the above, then i have run out of ideas, i had a similar issue a while back with Just cause 2. I backed up all my data and unfortunately had to reinstall my windows. This did fix the problem though. Possibly perform a complete wipe of ALL GPU drivers right down to the registry entries. Might save yourself from having to do a full reboot. Let me know if this helps

Edit:
Also if you decide to do a driver wipe system wide, make sure you try running the game with ONE card attached to the motherboard, do both individually. Check all cables etc.

thanks for the reply, I suppose wiping all my GPU drivers is more appealing than an entire re-install. I'll probably try that next. I'll let you know how it goes.

*edit* disc version