Empty 'Tools->HTTPS Everywhere' menu in Firefox

Steps to reproduce with a clear profile:

1. Start Firefox.
2. Install HTTPS Everywhere and restart the browser as requested.
3. Remove HTTPS Everywhere icon from the browser's Navigation Toolbar (using the Customize feature).
4. Restart Firefox.
5. Expand the 'Tools' menu and try to see the content of the 'HTTPS Everywhere' menu item.

The menu item is empty and this error is logged:

Timestamp: 06/02/2012 02:21:32 PM
Error: TypeError: popup is null
Source File: chrome://https-everywhere/content/toolbar_button.js
Line: 45

Returning the toolbar icon back and restarting Firefox fixes the menu.

Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/15.0 Firefox/15.0a1