This question already has an answer here:
Pidgin's page in Software Center says I should install one of gnome-panel or kdebase-workspace-bin or docker to achieve this. I installed docker but nothing happened.
Needless to say, I have "Show system tray icon" set to "Always" in Pidgin's preferences.
This is not a duplicate question, because the Ubuntu 12.10 recipe doesn't apply to 13.04
I said, this question is not a duplicate. I'm saying it again: dconf-editor doesn't show the parameters that the answer on the OTHER question says I should edit. Because this here question refers to 13.04, and not to versions up to 12.10.