Only 8 thumbnails show up on my slightly customized Amsterdam theme

I have more than 8 projects with thumbnails all of the same size but only 8 show up even though more are switched on and there is space for more thumbnails no more show up. I have an upgraded account so there shouldn't be a problem there.

Perhaps its something I changed when customizing the CSS?

Would appreciate any thoughts or ideas... cargocollective.com/kirkmoore