I'm also experiencing this issue. The white rectangle appears intermittently and I haven't been able to determine what action triggers it. A reboot or logout seem to fix it.
-- You received this bug notification because you are a member of Unity API bugs, which is subscribed to The Sound Menu. https://bugs.launchpad.net/bugs/1068385 Title: rendering bug of the play button in 12.10 Status in Sound Menu: New Bug description: Since I upgraded to 12.10 today, the play button isn't rendered correctly. A white bordered rectangle appears on top of the play button in the sound indicator, as shown in the attachment. The version of the indicator-sound is: indicator-sound 12.10.1-0ubuntu1 Please ask if you need more information about my system. To manage notifications about this bug go to: https://bugs.launchpad.net/indicator-sound/+bug/1068385/+subscriptions -- Mailing list: https://launchpad.net/~unity-api-bugs Post to : [email protected] Unsubscribe : https://launchpad.net/~unity-api-bugs More help : https://help.launchpad.net/ListHelp

