occurred several times more after frequent periodic updates, 

Additional logs of auth.log specifying polkitd problems follow:

Apr  8 15:53:22 L1fu510n sudo: pam_unix(sudo:session): session opened for user root by (uid=1000)
Apr  8 15:53:40 L1fu510n sudo: pam_unix(sudo:session): session closed for user root
Apr  8 16:09:01 L1fu510n CRON[7069]: pam_unix(cron:session): session opened for user root by (uid=0)
Apr  8 16:09:01 L1fu510n CRON[7069]: pam_unix(cron:session): session closed for user root
Apr  8 16:17:01 L1fu510n CRON[7133]: pam_unix(cron:session): session opened for user root by (uid=0)
Apr  8 16:17:01 L1fu510n CRON[7133]: pam_unix(cron:session): session closed for user root
Apr  8 16:39:01 L1fu510n CRON[7198]: pam_unix(cron:session): session opened for user root by (uid=0)
Apr  8 16:39:01 L1fu510n CRON[7198]: pam_unix(cron:session): session closed for user root
Apr  8 16:44:13 L1fu510n polkitd(authority=local): Unregistered Authentication Agent for unix-session:/org/freedesktop/ConsoleKit/Session2 (system bus name :1.72, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8) (disconnected from bus)
Apr  8 16:44:51 L1fu510n login[1332]: pam_unix(login:session): session opened for user darian by LOGIN(uid=0)
Apr  8 16:44:56 L1fu510n sudo:   darian : TTY=tty1 ; PWD=/home/darian ; USER=root ; COMMAND=/bin/bash
Apr  8 16:44:56 L1fu510n sudo: pam_unix(sudo:session): session opened for user root by darian(uid=1000)


Apr  8 21:14:42 L1fu510n polkitd(authority=local): Unregistered Authentication Agent for unix-session:/org/freedesktop/ConsoleKit/Session2 (system bus name :1.72, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8) (disconnected from bus)
Apr  8 21:15:08 L1fu510n login[1340]: pam_unix(login:session): session opened for user darian by LOGIN(uid=0)
Apr  8 21:15:17 L1fu510n sudo:   darian : TTY=tty1 ; PWD=/home/darian ; USER=root ; COMMAND=/sbin/reboot
Apr  8 21:15:17 L1fu510n sudo: pam_unix(sudo:session): session opened for user root by darian(uid=1000)
Apr  8 21:15:17 L1fu510n sudo: pam_unix(sudo:session): session closed for user root
Apr  8 21:15:55 L1fu510n lightdm: pam_unix(lightdm:session): session opened for user lightdm by (uid=0)
Apr  8 21:15:55 L1fu510n lightdm: pam_ck_connector(lightdm:session): nox11 mode, ignoring PAM_TTY :0
Apr  8 21:15:56 L1fu510n lightdm: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "darian"
Apr  8 21:15:56 L1fu510n dbus[853]: [system] Rejected send message, 2 matched rules; type="method_call", sender=":1.43" (uid=104 pid=1727 comm="/usr/lib/indicator-datetime/indicator-datetime-ser") interface="org.freedesktop.DBus.Properties" member="GetAll" error name="(unset)" requested_reply="0" destination=":1.34" (uid=0 pid=1435 comm="/usr/sbin/console-kit-daemon --no-daemon ")
Apr  8 21:16:33 L1fu510n lightdm: pam_unix(lightdm:session): session closed for user lightdm
Apr  8 21:16:33 L1fu510n lightdm: pam_unix(lightdm:session): session opened for user darian by (uid=0)
Apr  8 21:16:33 L1fu510n lightdm: pam_ck_connector(lightdm:session): nox11 mode, ignoring PAM_TTY :0
Apr  8 21:16:37 L1fu510n dbus[853]: [system] Rejected send message, 2 matched rules; type="method_return", sender=":1.3" (uid=0 pid=887 comm="/usr/sbin/bluetoothd ") interface="(unset)" member="(unset)" error name="(unset)" requested_reply="0" destination=":1.71" (uid=1000 pid=1945 comm="/usr/bin/gnome-shell ")
Apr  8 21:16:38 L1fu510n polkitd(authority=local): Registered Authentication Agent for unix-session:/org/freedesktop/ConsoleKit/Session2 (system bus name :1.73 [/usr/bin/gnome-shell], object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8)
Apr  8 21:17:00 L1fu510n CRON[2213]: pam_unix(cron:session): session opened for user root by (uid=0)
Apr  8 21:17:00 L1fu510n CRON[2213]: pam_unix(cron:session): session closed for user root
Apr  8 21:17:06 L1fu510n sudo:   darian : TTY=unknown ; PWD=/home/darian ; USER=root ; COMMAND=/usr/bin/nautilus
Apr  8 21:17:06 L1fu510n sudo: pam_unix(sudo:session): session opened for user root by (uid=1000)
Apr  8 21:17:54 L1fu510n sudo: pam_unix(sudo:session): session closed for user root
Apr  8 21:22:05 L1fu510n polkitd(authority=local): Unregistered Authentication Agent for unix-session:/org/freedesktop/ConsoleKit/Session2 (system bus name :1.73, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8) (disconnected from bus)
Apr  8 21:22:33 L1fu510n login[1322]: pam_unix(login:session): session opened for user darian by LOGIN(uid=0)
Apr  8 21:22:37 L1fu510n sudo:   darian : TTY=tty1 ; PWD=/home/darian ; USER=root ; COMMAND=/bin/bash
Apr  8 21:22:37 L1fu510n sudo: pam_unix(sudo:session): session opened for user root by darian(uid=1000)

Please let me know of any additional info needed, it is starting to become quite frustrating...

Thanks