Screen Blacks Out at Certain POVs

[wahoozerman]

At certain points of view while playing Requiem my screen will go completely black, and occasionally will flicker to the desktop before returning to rendering the game.

The only similarities I can find in the points of view for which this happens is that it seems to be in areas that connect two larger rooms, such as doorways or arches, and the viewpoint on the horizontal axis is usually close to perpendicular to the flow from one room to the next. (If you need help visualizing, go stand in the middle of a doorway and look at the door frame.)

Additionally, this problem doesn't happen if I turn shadows completely off, but that kind of ruins the game.

Off the top of my head, it seems like it might have something to do with Area Portals or the splits between visleafs, but I don't know how/if your engine handles those.

PC Specs:

Intel core 2 duo 2.4ghz
2 Nvidia 9800 GTX+ (SLI)
4GB Kingston HyperX Ram
EVGA 780i SLI motherboard
Creative Sound Blaster Audigy 2 ZS Sound Card
Windows Home Premium 64 bit.

Graphics Driver: Nvidia 258.96_desktop_winvista_64bit_english_whql

I have tried turning off SLI and even physically removing a graphics card, but no luck there. This has happened across several sets of Nvidia drivers. This does not happen on Overture or Black Plague.

DxDiag is attached.