I tried to follow the directions in the readme for setting up vncboot. When I copy and pasted the text as is into the vncboot file, it didn't work because the exec fails to run the script since the first line is a comment.
I moved the #! /bin/sh to the first line from the 10th line or so, and it worked properly.
I was using the following image: 2015-09-24-raspbian-jessie.img running on a Raspberry Pi 2 B V1.1