The downloads panel button is always present in the navigation toolbar. When I try to customize the navigation toolbar (right click -> customize...) the downloads panel button disappears, and is not listed in the context pane for customizing the toolbar. I expect to be able to move the downloads panel button like any other UI button element (panorama, print, addon buttons, etc) Using Firefox Nightly 14.0a1 (2012-04-18)

Duplicate of Bug 746772.