[Plugin: SidePosts Widget] Sideposts will not work

I have installed the sideposts plug-in. When I access the widget menu it allows me to put sideposts into my sidebar frame. But after I save the settings and access my page, it does not show up. When I return to the widget menu the sideposts widget has disappeared from my active sidebar frame.

http://wordpress.org/extend/plugins/sideposts/