I have same problem on my work and home PC both.

Log:

$ cat ~/.cache/upstart/gnome-settings-daemon.log
(gnome-settings-daemon:2318): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:2318): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:2318): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:2318): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:2318): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:2318): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:2318): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:2318): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:2318): GLib-CRITICAL **: Source ID 55 was not found when attempting to remove it
** (gnome-settings-daemon:5435): WARNING **: Name taken or bus went away - shutting down
(gnome-settings-daemon:5435): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:5435): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:5435): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:5435): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:5435): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:5435): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:5435): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:5435): wacom-plugin-CRITICAL **: gsd_wacom_device_get_device_type: assertion 'GSD_IS_WACOM_DEVICE (device)' failed
(gnome-settings-daemon:5435): GLib-CRITICAL **: Source ID 56 was not found when attempting to remove it
** (gnome-settings-daemon:7346): WARNING **: Name taken or bus went away - shutting down
** (gnome-settings-daemon:7351): WARNING **: Name taken or bus went away - shutting down
** (gnome-settings-daemon:7355): WARNING **: Name taken or bus went away - shutting down
** (gnome-settings-daemon:7359): WARNING **: Name taken or bus went away - shutting down
** (gnome-settings-daemon:7363): WARNING **: Name taken or bus went away - shutting down
** (gnome-settings-daemon:7367): WARNING **: Name taken or bus went away - shutting down
** (gnome-settings-daemon:7371): WARNING **: Name taken or bus went away - shutting down
** (gnome-settings-daemon:7375): WARNING **: Name taken or bus went away - shutting down
** (gnome-settings-daemon:7379): WARNING **: Name taken or bus went away - shutting down
** (gnome-settings-daemon:7383): WARNING **: Name taken or bus went away - shutting down
** (gnome-settings-daemon:7387): WARNING **: Name taken or bus went away - shutting down