Miscalculation width Container

[pinin]

Hello, first thanks for the great plugin.
I have a problem calculating the width of the container.
emementu sizes are 80, 160, 320 defined in the CSS.
When using the plugin but the width is calculated incorrectly and forum containers element is visible only in part.

.js
var $container = $('.list-item-container');
$container.isotope({
layoutMode: 'perfectMasonry',
perfectMasonry: {
layout: 'horizontal',
liquid: false,
columnWidth: 80,
rowHeight: 80
}
});

html:
<div>
<div class="group-box">
<div class="group-box-heading">
...
</div>
<div class="group-box-content">
<div class="list-item-container">
<div class="tile wide2">
...
</div>
<div class="tile wide2">
...
</div>
<div class="tile">
...
</div>
</div>
</div>
</div>
<div class="group-box">
....
</div>
</div>
Can you please help?
thank