Does Yellow Pencil cause inconsistencies with certain Wordpress themes. Above site has Blog Lite theme. When YP deactivated, site seems to respond better to differing browser widths.
Yellow Pencil is a style editor which help you to edit your
website visually. May you must be careful while editing the sizes
and position on your site. You must test your site with Responsive Tool before saving
I recommend you to read all plugin documentation for use the plugin
I'm hope thats help,