2.12 did not include the patch you referenced. Or if it did the patch didn't resolve the problem of same user in two xsessions missing icons and also missing mouse controls in the second xsession.
apt-cache show gnome-control-center
Package: gnome-control-center
Priority: optional
Section: gnome
Installed-Size: 1644
Maintainer: Arnaud Patard <[EMAIL PROTECTED]>
Architecture: i386
Source: control-center
Version: 1:2.12.3-2
Replaces: capplets
Provides: capplets
Depends: libart-2.0-2 (>= 2.3.16), libatk1.0-0 (>= 1.9.0), libaudiofile0 (>= 0.2.3-4), libavahi-client3 (>= 0.6.0), libavahi-common3 (>= 0.6.4), libavahi-compat-howl0 (>= 0.6.0), libbonobo2-0 (>= 2.8.0), libbonoboui2-0 (>= 2.5.4), libc6 (>= 2.3.5-1), libcairo2 (>= 1.0.2-2), libdbus-1-2 (>= 0.60), libebook1.2-5 (>= 1.4.2.1), libesd0 (>= 0.2.35) | libesd-alsa0 (>= 0.2.35), libfam0, libfontconfig1 (>= 2.3.0), libfreetype6 (>= 2.1.5-1), libgconf2-4 (>= 2.11.1), libgcrypt11 (>= 1.2.2), libglade2-0 (>= 1:2.5.1), libglib2.0-0 (>= 2.8.5), libgnome-desktop-2 (>= 2.11.1), libgnome-keyring0 (>= 0.4.3), libgnome-menu2, libgnome2-0 (>= 2.8.0), libgnomecanvas2-0 (>= 2.11.1), libgnomeui-0 (>= 2.8.0), libgnomevfs2-0 (>= 2.12.0), libgnutls11 (>= 1.0.16), libgpg-error0 (>= 1.1), libgstreamer-plugins0.8-0 (>= 0.8.0), libgstreamer0.8-0 (>= 0.8.11), libgtk2.0-0 (>= 2.8.0), libice6, libjpeg62, libmetacity0 (>= 1:2.12), libnautilus-extension1 (>= 2.9.1), liborbit2 (>= 1:2.10.0), libpango1.0-0 (>= 1.10.3), libpng12-0 (>= 1.2.8rel), libpopt0 (>= 1.7), libsm6, libstartup-notification0 (>= 0.8-1), libtasn1-2 (>= 0.2.13), libx11-6, libxcursor1 (>> 1.1.2), libxext6, libxft2 (>> 2.1.1), libxi6, libxinerama1, libxklavier10, libxml2 (>= 2.6.23), libxrandr2, libxrender1 (>= 1:0.9.0.2), libxss1, libxxf86misc1, zlib1g (>= 1:1.2.1), capplets-data (= 1:2.12.3-2), gnome-menus, gnome-desktop-data, gnome-icon-theme (>= 1.2.3-1), xlibs, desktop-file-utils
Recommends: gnome2-user-guide, gnome-session
Suggests: esound-clients, xscreensaver (>= 4.0) | gnome-screensaver, xbase-clients, gstreamer0.8-alsa | gstreamer0.8-oss | gstreamer0.8-esd
Conflicts: capplets
Filename: pool/main/c/control-center/gnome-control-center_2.12.3-2_i386.deb
Size: 643310
MD5sum: ebd2e5782f697bdb10c52326e51f7956
Description: utilities to configure the GNOME desktop
This package contains configuration applets for the GNOME desktop,
allowing to set accessibility configuration, desktop fonts, keyboard
and mouse properties, sound setup, desktop theme and background, user
interface properties, screen resolution, and other GNOME parameters.
.
It also contains a front end to these applets, which can also be
accessed with the GNOME panel or the Nautilus file manager.
Tag: interface::x11, made-of::lang:c, role::sw:application, suite::gnome, uitoolkit::gtk, use::configuring, x11::application
