Had a terminal crash this evening where I had imported the diffuse from a previously textured iteration, had done some adjustments to the sculpting and diffuse and when I went to save, it crashed. Just previous to saving I had attempted to use the clone brush on the diffuse and I had a big red warning that it couldnt find the little diffuse background texture and another texture file with the pathname to my previous iteration.

Is there something special you have to do with these background files, like transfer them over if you import textures?