Hi,
This is a known problem.
The solution is extremely easy.
Open this JS file:
/templates/flexible_lightmart/js/template.js
Remove those 2 lines completely. (22nd and 23rd)
var ProductDetailsFixheight = $('#vmFlyPageTop').height();
$('#vmFlyPageTop').css("height",ProductDetailsFixheight);
This will fix the issue.
Regards.
Support & Development.