I have tried to slice http://www.thingiverse.com/thing:21773/#files and http://www.thingiverse.com/thing:16343
I have created two processes, One for print head one and another for print head two.
I have assigned each stl file to each extruder.
On prepare I select both FFF processes
Continuous is selected.
When the gcode is generated I get the following:
I do this all the time in Slic3r with no issues.
Let me know what I am doing wrong.