Not using any of that kind of footage. Like I said, most of it made from scratch within AE, with the exception of one JPG image and one Photoshop PSD image.
It fails to render at a seemingly random point too, as it is at a point where I have some text flying across the screen. However, that same text flies across the screen earlier in the composition, and it renders fine then. Likewise, the jpg and psd are on-screen for a while before the failure point. So if it means anything, no new elements are appearing on-screen at the point that it fails, or refuses to RAM Preview.