The same here.
$ uname -a
Linux connie-desktop 4.10.0-38-generic #42~16.04.1-Ubuntu SMP Tue Oct 10
16:32:20 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
$ free -m
totalusedfree shared buff/cache available
Memory:39393040 156 97
Ubuntu 10.04
I've caught this bug.
this - https://bugs.launchpad.net/gnome-control-
center/+bug/147045/comments/15 solves the problem.
Here is the content of my .gtkrc-2.0
# -- THEME AUTO-WRITTEN DO NOT EDIT
include /usr/share/themes/Glossy/gtk-2.0/gtkrc
include /home/connie/.gtkrc.mine
apt-get upgrade
Now I can switch between users and logging out at any moment.
$ nvidia-settings -q NvidiaDriverVersion
Attribute 'NvidiaDriverVersion' (connie-desktop:0.0): 173.14.27
$ uname -a
Linux connie-desktop 2.6.32-25-generic #43-Ubuntu SMP Wed Sep 1 09:46:39 UTC
2010 i686 GNU/Linux