Comment 3 for bug 152107

lpadmin is in the profile here - I also reconfirmed that new users are not added to the lpadmin group after seeing this.
The same thing seems to happen for the video group; it's listed, but not added/

/etc/gnome-system-tools/users/profiles:
[Unprivileged]
name=Unprivileged
name[es]=Usuario sin privilegios
shell=/bin/bash
home-prefix=/home
uid-min=1000
uid-max=6000

[Desktop]
name=Desktop user
name[es]=Usuario del escritorio
default=1
shell=/bin/bash
home-prefix=/home
uid-min=1000
uid-max=6000
groups=cdrom,floppy,dialout,tape,dip,adm,plugdev,fax,audio,scanner,fuse,lpadmin,video

[Administrator]
name=Administrator
name[es]=Administrador
shell=/bin/bash
home-prefix=/home
uid-min=1000
uid-max=6000
groups=cdrom,floppy,dialout,tape,dip,adm,plugdev,fax,audio,scanner,fuse,admin,lpadmin,video