Thanks for the response, Steve. As it turns out, I did have an ecosystem on my terrain... maybe even dozens???

Since I could no longer save the scene I was working on, I tried saving it out as vob files to rebuild. That, Vue would let me do. As a precaution, I thought I removed the 2 ecosystems I had on the terrain before vob'ing. Upon import of the terrain in a clean file, it seemed eco-less... no questions about auto-populating, and no eco icons on the mat preview. What I discovered later was that this almost empty scene saved at 78MB, just for standard terrain at 1024. Should've saved at 2MB (this was before adding the Poser figures). Anyways, when I tried to examine the terrain's mixed material, the ecosystems were showing up at every level, til I got 5 levels deep. At that point Vue went nuts. Graphics were jumping and flashing all over the place, immediately followed by a series of OOM errors. Even after Vue shut down, the OOM errors kept popping up. All this for 5 rocks, 3 plants, and 2 objects (aprox 40,000 polys each). I'd like to send this to tech support, but how do you pack up a file that won't save?