just to confirm - IBL can be used with ray-traced shadows, if one wants to avoid AO and speed things up. poser turns off shadows on me, as well, when changing from a directional lite to an IBL. as mentioned, this is likely due to the coders' belief that one should use AO with IBL, and not shadows, perhaps in regard to users' inability to understand shadowlite cams, map size, et al. displacement bounds seem to change at random. I don't know if render settings for DB over-ride object properties DB, but it's the object properties DB that change.