I have 12.04.1 LTS (64), and I just realised that this affected me too.
Updating /usr/share/applications/gnome-online-accounts-panel.desktop fixed this as per Antonio's comment.
Before
OnlyShowIn=GNOME;
After
OnlyShowIn=GNOME;Unity;
This took immediate effect. Log out was not required.
I have 12.04.1 LTS (64), and I just realised that this affected me too. applications/ gnome-online- accounts- panel.desktop fixed this as per Antonio's comment.
Updating /usr/share/
Before
OnlyShowIn=GNOME;
After GNOME;Unity;
OnlyShowIn=
This took immediate effect. Log out was not required.