IM-Settings-Daemon エラー

Issue

root ユーザーと UID/GID が同じである一般ユーザーがシステムにログインすると、Gnome ウィンドウに以下のエラーメッセージがポップアップ表示され、日本語を入力することができません。

IM-Settings-Daemon[4938]:CRITICAL **:Giving up to bring the process up because Main Input Method process for IBus rapidly died many times.See .imsettings.log for more details.

$HOME/.imsettings.log には、以下のメッセージが表示されます。

imsettings information
==========================
Is DBus enabled: yes
Is imsettings enabled: yes
Is GTK+ supported: yes
Is Qt supported: no
DESKTOP_SESSION: gnome
DISABLE_IMSETTINGS: 
IMSETTINGS_DISABLE_DESKTOP_CHECK: 
DBUS_SESSION_BUS_ADDRESS: unix:abstract=/tmp/dbus-hMKRyZc5nK,guid=42b52474f2707031beaf2fe000323d7d
GTK_IM_MODULE: 
QT_IM_MODULE: xim
XMODIFIERS:@im=ibus
IMSETTINGS_MODULE:IBus
IMSETTINGS_INTEGRATE_DESKTOP: yes


IM-Settings-Daemon[15966]:WARNING **:Unable to monitor /home/user/.xinputrc:Error stating file '/home/user/.xinputrc':No such file or directory
IM-Settings-Daemon[15966]:INFO:Started IBus: process:/usr/bin/ibus-daemon -r --xim, lang=ja_JP.UTF-8, pid:16162, id:13, time:2013-04-22T08:41:29.107411Z
IM-Settings-Daemon[15966]:INFO:Current IM is:IBus
IBus[16162]:Please run ibus-daemon with login user!Do not run ibus-daemon with sudo or su.

IM-Settings-Daemon[15966]:WARNING **:Main Input Method process for IBus died with the status 255, but unexpectedly. restarting...
IM-Settings-Daemon[15966]:INFO:Started IBus: process:/usr/bin/ibus-daemon -r --xim, lang=ja_JP.UTF-8, pid:16189, id:17, time:2013-04-22T08:41:29.251520Z
IBus[16189]:Please run ibus-daemon with login user!Do not run ibus-daemon with sudo or su.

IM-Settings-Daemon[15966]:WARNING **:Main Input Method process for IBus died with the status 255, but unexpectedly. restarting...
IM-Settings-Daemon[15966]:INFO:Started IBus: process:/usr/bin/ibus-daemon -r --xim, lang=ja_JP.UTF-8, pid:16209, id:20, time:2013-04-22T08:41:29.335506Z
IBus[16209]:Please run ibus-daemon with login user!Do not run ibus-daemon with sudo or su.

IM-Settings-Daemon[15966]:CRITICAL **:Giving up to bring the process up because Main Input Method process for IBus rapidly died many times.See .imsettings.log for more details.