Mistake with the sidebar widget

Hello, first congratulate you on the plugin.

I tell you, when I put the widget right on top of another widget, all other widgets that go under burrow into “<div class=”widget-container”>” does not appear as whole, it’s like missing a div that encompasses the widget widget-container and widget-top of the NivoSlider

http://wordpress.org/extend/plugins/nextgen-nivoslider/