Right clicking on an icon of a removable device in the message tray shows a popup menu that disappear as soon as the mouse moves. This applies to gnome 3.6 too but as far as I know the only upstream patch avaiable for this is for gnome 3.8. Here's the link to the relevant bug in gnome's bugzilla where the issue has been fixed: https://bugzilla.gnome.org/show_bug.cgi?id=700190 That patch should be included.
The fix is included in gnome-shell 3.8.3 which is currently in testing.