Portfolio Grid breaks when Sortable is set to yes

Hi, I’ve got a problem with the portfolio grid not working when it is set to yes. I’m on WordPress 3.6.

You can see a working version of the portfolio grid, without sortable at http://entecinc.com/projects/

You can see a non working version of the portfolio grid, with sortable at http://entecinc.com/entec-projects/

Any idea what may be causing the big blank space, and the portfolio items being blank boxes?

Thanks!