Defragging didn't help much. I'll try and explain a bit better. When I open my file and immediately do a Final Renderworks w/ Shadows, it takes about a minute, tops, to render. Then I'll go back to wireframe, make changes to something, go back to my camera view and render again, no problems. After rerendering five or six times, I get a "Lack of Memory" message, and I can't render any more. I save, close VW, then relaunch it and my file, and once again, I am able to Render another five or so times. So, some sort of cache is filling up everytime I render, and when I close VW, it clears it out and allows me to render again. Is there something in the preferences I am missing?