hmm That's weird. I have looked in Cura, Netfabb and Cinema 4D. But cant find any problems anywhere.
So Im not sure whats going on here, I'll keep an eye out if I hear more people having the same problem.
I have re-uploaded the "track.stl" file with one little adjustment, but that doest resemble the problems in your picture.
As far as i know Cura should work perfectly