this bug affected me when I enabled the Notification Area (Systray) for all the applications with this command:
gsettings set com.canonical.Unity.Panel systray-whitelist "['all']"
restoring the setting to the original value solve the problem
gsettings set com.canonical.Unity.Panel systray-whitelist "['JavaEmbeddedFrame', 'Mumble', 'Wine', 'Skype', 'hp-systray']"
However, with the default setting some other systray icon, like gmusicbrowser, are not shown in the systray
this bug affected me when I enabled the Notification Area (Systray) for all the applications with this command:
gsettings set com.canonical. Unity.Panel systray-whitelist "['all']"
restoring the setting to the original value solve the problem
gsettings set com.canonical. Unity.Panel systray-whitelist "['JavaEmbedded Frame', 'Mumble', 'Wine', 'Skype', 'hp-systray']"
However, with the default setting some other systray icon, like gmusicbrowser, are not shown in the systray