This problem will not be specifically Mac related, and also I am not able to help much without more detailed information. How do you know it didn't work, were there any errors? Did it crash? What were you doing before? What sort of files do you have?
If by label you mean title, you probably need to put the files if they are named [title]5, in the preset 5 folder, unless you have a .mat file with it. Otherwise, each folder has a .mat file in it already that references certain named files. (folder 1 has a .mat folder that references [title]1 image files)
I hope this helps, shadowmoon.