Domain User cannot mount USB or shutdown

Question

Hello,
after a few weeks when I installed Samba and joined a Domain I realized that when I put in an USB stick my file manager tells me that this operation is not allowed. So I have to mount the USB stick with sudo. Did I make something wrong in the PAM configuration? My domain user is in the local group of storage and power ...
It would be great if some one can give me some direction where to look for the problem.
Regards
Debellator

Answer 1

Thanks for your fast response.
When there is a kernel update I do a restart.
I do not use a login manager.
#!/bin/sh
# ~/.xinitrc
# Executed by startx (run your window manager from here)
if [ -d /etc/X11/xinit/xinitrc.d ]; then
for f in /etc/X11/xinit/xinitrc.d/*; do
[ -x "$f" ] && . "$f"
done
unset f
fi
setxkbmap de
# exec gnome-session
# exec startkde
# exec startxfce4
# ...or the Window Manager of your choice
exec ck-launch-session startlxde