Under Theme Options > Blog Layout, I have Photo Wall With No Sidebar selected. It shows 10 photos by default, over 3 columns. This leaves a hanging photo at the bottom before it pushes photos to a new page. I would like to limit the photos shown on the Photo Wall to a multiple of 3 but do not see the option.
I am glad to know that you have found it. Do you mind replying with where you found it so that other users can also read this in case they do not find it?