Torbutton not showing up on Mac OS X 10.6.6/7 with Firefox 4.0

vidalia 0.2.10 and polipo (version as bundled with vidalia) start up fine, test in torbutton preferences reports success but no button to activate/deactivate torbutton shows up in neither the tool, status nor add-on bar

This happens with torbutton 1.3.1-alpha and 1.3.2-alpha

Besides torbutton the following add-ons are installed

• Adblock Plus 1.3.3
• BetterPrivacy 1.49
• DOM Inspector 2.0.9
• DownloaddHelper 4.8.4
• Firebug 1.7.0
• User Agent Switcher 0.7.3

Trac:
Username: torifiedUser