Objects were disappearing in the world. We tracked it down to the texture streaming system. As we stream textures into and out of the video card the memory is getting fragmented so that a larger set of textures cannot find room to be loaded.
In order to fix this issue we have to write video 'chunk' system to guarantee that memory does not get fragmented in the future. Separate systems were needed for dynamic and static geometry. We're getting started on that code now.