Blender crashing on large scenes (and a quick fix)

I kept having trouble with a large scene I had built around an exported Daz Studio figure, with the GPU not being able to handle all the texture files associated with the character.

I tried splitting up the character into parts, with it and various parts of the scene on different layers (until then, I had never tried multi-layer rendering, in fact). My GTX 670 only has 2GB of VRAM so even that’s too much, apparently. Even with the scene split up into layers, it still chokes on it.

I eventually decided to render the background in GPU mode (which is mostly made with procedural textures, save the wood flooring), and then render the character in CPU mode (which wouldn’t take very long since it’s much smaller than the whole scene). Unfortunately every time I tried this, Blender crashed.

However I finally tried rendering in Fullscreen Mode and that seemed to stop the crashing – I’ve not had another crash since. Rendering in Image Editor is what made it crash.

Any ideas on why it does this?