Just recently finished my build and it's up and running. The only issue I've had is the monitor will turn off from time to time while playing Dark Age of Camelot. I will also note that this has never happened during any other game. I've played Dead Rising 2/Left4Dead 2/etc. for hours at a time and it has only happened on DAoC.
Right before it happens, the game freezes for a second or two, followed by the 2-3 seconds of black screen. The display then returns to normal and everything is fine. No chopiness, lag, nothing. This probably happens once an hour if I had to approximate. It is not consistent and seems to have no predictive quality.
This also never happens during regular computer use. Surfing, Skyping, instant messenging, etc. I haven't been able to replicate the problem outside of this specific game.
One might think that this is a problem with the specific game, but I doubt any single game could actually turn off the monitor itself and then turn it back on. It sounds like a GPU or connection issue, but the fact that it only seems to happen on one game is bizarre.
Temps are great. 50*C on my GTX 460 under gaming load for 3-4 hours, ~45*C on my i5-760. RAM is OC'd to 1600 (it's the notorious G.Skill that is advertised at 1600 but 1600 is actually an OC). Using the XMP profile, it puts the RAM at 7-8-7-24 with 1.6 as per manufacturer guidelines. I mention temperatures because this has happened to previous PCs that I've owned because of overheating issues. When it DID happen, however, the display would not come back and would require a reboot (coupled with the yellow 'standby' light on the monitor). Not the case here. Monitors turns off, comes back on.
There are no loose connections on the monitor or GFX card. It's random and not even annoying, but I'd like to correct it if possible.