I put both. OBJ format imports like their textures in the same directory as the geometry. Also, when I've made props in the past I've made bad texture references that bit me later, so I thought I'd eliminate that problem. Once a prop is in the library, the copy of the geometry can be deleted from Textures.

I was thinking that, since some unfamiliar bug involving textures was popping up, maybe there was bad internal data being generated when the OBJ or other geometry was imported that didn't show up until new props were spawned.