Plan Labels Popup ShortCut Not Working As Expected

On the Plan dashboard (/browse/PROJKEY-PLANKEY/) I press the L key which is supposed to be a shortcut to open the Labels window popup. The popup opens fine. The title of the popup is Plan Labels. I then click the Close link on the popup window and instead of closing as expected the popup window flashes suddenly but stays on the screen. The title of the popup window now simply says "Labels" instead of "Plan Labels". If I click the close link a 2nd time the window finally closes.

This same behavior occurs in Firefox 16, Safari 5.1, and Internet Explorer 8.

Note : I did not report this to Support as I am not running Bamboo 4.3 in production and am only doing local testing.