Yes, I am using Repetier Host for viewing and running the printer (these are printed on a Printrbot Metal Simple, not an Ultimaker).
I was using a .4mm nozzle, .8mm shell thickness, 100% infill. Retraction was enabled, set to 3mm.
Changing the infill has no effect on this. Even setting infill to 0% results in the same path generation in the thin wall areas. So it appears that the paths are being generated as part of the perimeter, not infill, calculations.
As a note, the Cura print specified using about 10 percent more filament than the Slic3r.
I'm fine with using which ever slicing program will yield the better results on ant given part, so Slic3r works out better for this one with thin walls, but Cura generates better support structures than Slic3r so there are times I'll want to use it instead, and maybe have thin walls. So I'm trying to figure out if there is a solution to this.
Thanks for the help!