JHtml::core(); -> JHtml::_('behavior.framework');

When testing this template with Joomla 3.1.1, line 14 (JHtml:core();) resulted in the page not rendering. Changing this to JHtml::_('behavior.framework'); (from the original component) seems to have fixed the problem.
Merge pull request #19 from 4web/patch-2

JHtml::core(); -> JHtml::_('behavior.framework');