I tried browsing through the last pages and using search and found nothing on this topic. So..
Lately on a scene that I've been testing my nature materials on, I've encountered a problem where my Forest objects mix materials up. For instance, my maple tree leaves get assigned the trunk material instead. My gut feeling is this has something to do with my recent switch to Vray proxies but I'm not sure. Any ideas? Using Vray 2.3 on Max 2012.