I had a similar problem recently and the fact that images are stacked one under another probably means that the script is not loading. However, if you resize the browser window a little bit, the script is triggered and images are places the way they should.
Wrap this code
imagesLoaded( '#thumbnailgallery', function(){
var $container = $('#thumbnailgallery');
$container.isotope({
itemSelector: '.element',
layoutMode: 'masonry',
masonryHorizontal: {
columnWidth: 240,
rowHeight: 240,
gutterwidth: 50},
});
});
in (document).ready function like this:
$(document).ready(function () {
imagesLoaded( '#thumbnailgallery', function(){
var $container = $('#thumbnailgallery');
$container.isotope({
itemSelector: '.element',
layoutMode: 'masonry',
masonryHorizontal: {
columnWidth: 240,
rowHeight: 240,
gutterwidth: 50},
});
});
});