This is pissing me off... I am trying to hide some icons in tray notification area because they look lame. So I went to the System Tray Setting, and got into the Entries tab. As you all know, this lists all the possible entries. So I went over to the desired app, and set it to 'Hidden'. What happened was very interesting. Instead of hiding the app I want it to, it sets the second entry to 'Shown' and leaves the desired entry as is. The setting does not respond afterwards (i.e. the menu moves but it does not save the desired changes). This persists until I remove the system tray from the panel and replace it with a new one. Sometimes, the whole thing crash when I save and then try to interact with the tray. Tried with Amarok and Clementine.
*** This bug has been marked as a duplicate of bug 1282417 ***