In Unity, I see running programs such as Dropbox or Pidgin in the taskbar (the icons also change when dropbox is updating or I have received a new message in Pidgin).
However, when I switched to GNOME these icons disappeared, even though the program is still running. A similar question was asked here:
Running programs are not displayed in the panel
But this question is for Ubuntu 10.x, and I don't see the "bottom panel" this question is referring to.
I have the same problem on my work and home PCs, so I suspect this is not an artefact of my particular installation.
How can I get these icons back?
3.9.90