Search result page, missing properties

I really like the plugin, but have some issue with the search result.
If I search for types or location the result page does not show all the properties, and not fill out the last row. One space is empty, even that I have much more properties to show.
http://www.metrowestcre.com/wp2/?s=&post_type=listing&property-types=industrial

Any hint how to fix this glitch?

Thanks,