Hey man! Glad you like the plugin. I'm GUESSING that you might want to adjust the width of your thumbnails in your CSS. I know, for example, that sometimes the widths are set with a percentage instead of px width. I use this code on my site to fix the same issue I was having with twentytwelve theme:
.gallery-item { min-width: 300px }
.gallery .gallery-icon img {
padding: 0 0 0 0 !important;
border: none !important;
}You may or may not need the border styles or padding. Also, the min-width should match the width of your thumbnails set in the Media section of the Dashboard. If this doesn't work, shoot me a link to your site and I can take a look at it.