I had a similar problem (Vue 7 Inf). I created a light panel and because an EcoSystem was the last material I'd use, Vue asked me if I wanted to populate the light panel. When I answered no, the terrain with the EcoSystem had the EcoSystem deleted and I had to start from scratch.

I've had quite a few instances where I lost my EcoSystem population, but can't give details at the moment. All very annoying.  :-(

Adriaan Barel (a.k.a. Vege Mite)
"Morality, like art, means drawing a line someplace." -- Oscar Wilde