This bug was fixed in the package gnome-session - 3.9.90-0ubuntu16
--------------- gnome-session (3.9.90-0ubuntu16) utopic; urgency=medium
* set GNOME_SHELL_SESSION_MODE for gnome-classic sessions (LP: #1381297) -- Tim Lunn <email address hidden> Wed, 15 Oct 2014 11:18:08 +0100
This bug was fixed in the package gnome-session - 3.9.90-0ubuntu16
---------------
gnome-session (3.9.90-0ubuntu16) utopic; urgency=medium
* set GNOME_SHELL_ SESSION_ MODE for gnome-classic sessions (LP: #1381297)
-- Tim Lunn <email address hidden> Wed, 15 Oct 2014 11:18:08 +0100