0. Try just to update the theme https://cosmothemes.zendesk.com/entries/24038176-How-to-update-the-theme . If that won't work, go to next step.
1. Open the theme editor and localize the functions.php file.
2. Find the isotope script and it's localization, and change the hook name ('masonry' -> 'newmasonry'.
Here is an easy-to-get screenshot http://i.imgur.com/MvkGpuD.png
After saving the file, you should not have issues related to that. But of course, if you feel that something's not right, please give us a beep on https://cosmothemes.zendesk.com/home by opening a ticket and fully explaining the problem.
functions.php · /trunk/themes/afternight
functions.php · /trunk/themes/belief
functions.php · /trunk/themes/diggity
functions.php · /trunk/themes/gameover
functions.php · /trunk/themes/skyray
functions.php · /trunk/themes/ushop
We wish you a great day! Cheers!