I am going to say it now. Simplify3D has an absolutely #@$#@$#@ slicer.
This model slices perfectly in every single program but S3D doesn't like it. Why, I don't know and to be honest, am over giving a damn. It's the only program for printing I've paid money for ($100!) and it is an over-bloated piece of rubbish. It's 10 open source programs all thrown into one, its a frigging mess.
Thanks Tails for the original, I was going to print it out but both slicing and the base the bust was on both created issues and alot of extended printing time and supports. I wiped the base completely, rotated the bust a little and repaired it properly so it now slices fine.