ESSENTIAL GRID leaving spaces

http://modelbillboard.net/sp/

i keep getting spaces on my grid on the last row, 1 to 2 or 3 depending on what browser i use.

I have deleted numerous pics, galleries, categories, tried tag versus category for
blog selection and I still keep getting a blank or two. I do not having any extra blog
posts, they all show and moving the dates of publish don’t stop or move the issue either.

I was digging the look but don’t want to continue til i know i don’t need to redo posts.

thank you!