OK, I've raised an issue for this on github but there is no way of posting the files there so I'm doing so here. Everyone is welcome to have a look and come up with ideas.
I'm trying to do a better quality print of the Luxo Jnr Snap Together from thingiverse. Part of my problem is that the lamp shade is difficult to print if the STL is just dropped on the platter so I spun it around so it sits on the flat lamp end and asked Slic3r to generate support material in the hopes that it would support the overhang formed by the hole/bush where the lamp connects to the rest of the assembly. Slic3r did not generate any support material under this point so it won't print properly.
stl, gcode and config.ini file
Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9