Sidebar mix with footer

Hey thanks for your great plugin !

I have an issue though, I checked “Fixed Widget” in one of my Widget, but when I scroll down it seems the widget merges with the footer

Screen : http://www.toopix.eu/userfiles/1d36afd63c883aac77364d203236c46f.png

Is there anything I can do to fix that ?

Best regards

http://wordpress.org/plugins/q2w3-fixed-widget/