Layout Keeps Changing

Hello 🙂

I’m currently using this plugin over here: http://bourne.noyadesigns.com/gallery

However, if you look at the photo galleries over here, they fill out the container from edge to edge.
http://bourne.noyadesigns.com/wedding/
http://bourne.noyadesigns.com/maternity/
http://bourne.noyadesigns.com/portrait/

However, this page sometimes it does that, sometimes it doesn’t. How do I get it to fill the container properly please?

Thanks!