Hola a todos y gracias por contestar.
Si pongo lo mismo con sudo me dice que no se encuentra el archivo.
Aqui va el resultado de poner en la consola lo que me dijo JanKusanagi:
ls -l /home/aldaril/.config/menus Permiso denegado
ls -l /home/aldaril/.config Permiso denegado
ls -la /home/aldaril Aquí sale el siguiente tocho:
total 708
drwxr-xr-x 60 aldaril aldaril 4096 2007-11-11 07:24 .
drwxr-xr-x 3 root root 4096 2007-10-24 09:31 ..
-rw-r--r-- 1 aldaril aldaril 788 2007-10-31 17:46 .acidriprc
drwxr-xr-x 4 aldaril aldaril 4096 2007-10-26 04:38 .adobe
drwx------ 4 aldaril aldaril 4096 2007-11-11 07:38 .aMule
drwx------ 2 aldaril aldaril 4096 2007-10-24 09:56 .aptitude
drwx------ 2 aldaril aldaril 4096 2007-11-11 07:23 .aqualung
-rw-r--r-- 1 aldaril aldaril 24 2007-10-25 05:14 .aspell.en.prepl
-rw-r--r-- 1 aldaril aldaril 22 2007-10-25 05:14 .aspell.en.pws
-rw-r--r-- 1 aldaril aldaril 123 2007-11-11 07:35 .aspell.es.prepl
-rw-r--r-- 1 aldaril aldaril 220 2007-11-11 07:35 .aspell.es.pws
drwxr-xr-x 4 aldaril aldaril 4096 2007-11-11 06:22 .audacity-data
drwxr-xr-x 3 aldaril aldaril 4096 2007-10-31 05:38 .avidemux
drwxr-xr-x 2 aldaril aldaril 4096 2007-10-24 19:21 .babytrans
-rw------- 1 aldaril aldaril 2939 2007-11-10 05:09 .bash_history
-rw-r--r-- 1 aldaril aldaril 220 2007-10-24 09:31 .bash_logout
-rw-r--r-- 1 aldaril aldaril 2298 2007-10-24 09:31 .bashrc
drwxr-xr-x 3 aldaril aldaril 4096 2007-10-24 16:53 .cache
drwxr-xr-x 5 aldaril aldaril 4096 2007-11-09 15:05 .cddb
drwx------ 4 root root 4096 2007-11-09 04:24 .config
drwx------ 3 aldaril aldaril 4096 2007-10-28 07:34 .dbus
-rw-r--r-- 1 aldaril aldaril 54 2007-11-11 02:47 .DCOPserver_Torpito__0
lrwxrwxrwx 1 aldaril aldaril 36 2007-11-11 02:47 .DCOPserver_Torpito_:0 -> /home/aldaril/.DCOPserver_Torpito__0
drwxr-xr-x 2 aldaril aldaril 4096 2007-10-28 08:33 .decibel-audio-player
drwx------ 4 aldaril aldaril 4096 2007-11-11 06:23 Desktop
-rw------- 1 aldaril aldaril 26 2007-10-24 08:51 .dmrc
drwxr-xr-x 8 aldaril aldaril 4096 2007-11-05 06:09 .dvdcss
drwxr-xr-x 2 aldaril aldaril 4096 2007-10-31 05:22 .dvdrip
-rw-r--r-- 1 aldaril aldaril 26185 2007-10-31 06:37 .dvdriprc
drwxr-xr-x 6 aldaril aldaril 4096 2007-11-10 16:53 .exaile
drwxr-xr-x 3 aldaril aldaril 4096 2007-10-26 05:02 .fltk
drwxr-xr-x 2 aldaril aldaril 4096 2007-11-05 02:57 .fontconfig
drwxr-xr-x 2 aldaril aldaril 4096 2007-10-26 03:54 .fonts
-rw-r--r-- 1 aldaril aldaril 514 2007-10-25 17:05 .fonts.conf
drwxr-xr-x 2 aldaril aldaril 4096 2007-10-24 18:56 .gaupol
drwx------ 3 aldaril aldaril 4096 2007-11-11 03:16 .gconf
drwx------ 2 aldaril aldaril 4096 2007-11-11 04:42 .gconfd
-rw-r--r-- 1 aldaril aldaril 249 2007-10-28 08:31 .gimmixrc
drwxr-xr-x 21 aldaril aldaril 4096 2007-10-25 06:45 .gimp-2.2
drwxr-xr-x 20 aldaril aldaril 4096 2007-11-11 04:37 .gimp-2.4
-rw-r----- 1 aldaril aldaril 0 2007-11-08 20:35 .gksu.lock
drwx------ 6 aldaril aldaril 4096 2007-10-28 07:34 .gnome2
drwx------ 2 aldaril aldaril 4096 2007-10-24 15:18 .gnome2_private
drwx------ 2 aldaril aldaril 4096 2007-10-26 04:50 .gnupg
-rw-r--r-- 1 aldaril aldaril 1530 2007-11-08 06:55 .grip
-rw-r--r-- 1 aldaril aldaril 66 2007-11-08 06:34 .grip-cdparanoia
-rw-r--r-- 1 aldaril aldaril 60 2007-11-08 06:55 .grip-flac
-rw-r--r-- 1 aldaril aldaril 100 2007-10-25 17:10 .grip-oggenc
drwxr-xr-x 2 aldaril aldaril 4096 2007-10-27 16:56 .gstreamer-0.10
-rw-r--r-- 1 aldaril aldaril 144 2007-11-04 16:34 .gtk-bookmarks
-rw-r--r-- 1 aldaril aldaril 25507 2007-10-24 15:18 .gtk_qt_engine_rc
-rw-r--r-- 1 aldaril aldaril 285 2007-10-24 08:51 .gtkrc-2.0-kde
-rw------- 1 aldaril aldaril 23146 2007-10-24 19:09 .hxplayerrc
-rw------- 1 aldaril aldaril 191 2007-11-11 02:47 .ICEauthority
drwxr-xr-x 2 aldaril aldaril 4096 2007-11-11 07:39 .incollector
drwxr-xr-x 3 aldaril aldaril 4096 2007-10-24 10:00 .java
drwxr-xr-x 5 aldaril aldaril 4096 2007-10-24 09:41 k3bmonkeyaudioplugin-3.1
drwx------ 5 aldaril aldaril 4096 2007-10-24 08:51 .kde
-rw------- 1 aldaril aldaril 160 2007-10-24 09:37 .kderc
drwxr-xr-x 4 aldaril aldaril 4096 2007-10-24 18:52 .kisotmp
-rw-r----- 1 aldaril aldaril 6 2007-11-05 07:52 .ktorrent.lock
drwx------ 3 aldaril aldaril 4096 2007-10-24 08:51 .local
-rw-r--r-- 1 aldaril aldaril 253 2007-11-05 04:18 .lpoptions
drwx------ 3 aldaril aldaril 4096 2007-10-24 14:21 .macromedia
drwxr-xr-x 3 aldaril aldaril 4096 2007-10-24 08:51 .mcop
-rw------- 1 aldaril aldaril 31 2007-10-31 04:39 .mcoprc
drwx------ 3 aldaril aldaril 4096 2007-10-24 15:18 .mozilla
drwxr-xr-x 2 aldaril aldaril 4096 2007-10-24 18:55 .mplayer
drwxr-xr-x 2 aldaril aldaril 4096 2007-10-24 16:56 .nted
drwx------ 3 aldaril aldaril 4096 2007-11-07 15:35 .openoffice.org2
drwx------ 12 aldaril aldaril 4096 2007-11-11 07:37 .opera
drwxr-xr-x 2 aldaril aldaril 4096 2007-11-01 06:45 .pdfedit
-rw-r--r-- 1 aldaril aldaril 566 2007-10-24 09:31 .profile
-rw------- 1 aldaril aldaril 256 2007-10-31 05:05 .pulse-cookie
drwxr-xr-x 3 aldaril aldaril 4096 2007-11-01 06:28 .qcomicbook
drwxr-xr-x 2 aldaril aldaril 4096 2007-11-11 02:47 .qt
drwxr-xr-x 4 aldaril aldaril 4096 2007-10-28 08:36 .quodlibet
-rw------- 1 aldaril aldaril 5818 2007-11-05 04:46 .recently-used
-rw-r--r-- 1 aldaril aldaril 20062 2007-11-11 07:23 .recently-used.xbel
drwxr-xr-x 2 aldaril aldaril 4096 2007-10-31 15:04 .ripdvd
drwxr-xr-x 3 aldaril aldaril 4096 2007-11-05 02:01 .smplayer
drwxr-xr-x 3 aldaril aldaril 4096 2007-10-27 00:53 .solfege
-rw-r--r-- 1 aldaril aldaril 2510 2007-10-27 00:57 .solfegerc
drwxr-x--- 2 aldaril aldaril 4096 2007-10-24 18:57 .somaplayer
drwx------ 4 aldaril aldaril 4096 2007-10-28 19:18 .strigi
-rw-r--r-- 1 aldaril aldaril 0 2007-10-24 09:01 .sudo_as_admin_successful
drwx------ 4 aldaril aldaril 4096 2007-10-24 09:15 .thumbnails
drwxr-xr-x 2 aldaril aldaril 4096 2007-10-27 08:51 .update-manager-core
drwxr-xr-x 2 aldaril aldaril 4096 2007-10-25 04:55 .VirtualBox
drwxr-xr-x 3 aldaril aldaril 4096 2007-10-28 03:43 .vlc
drwxr-xr-x 2 aldaril aldaril 4096 2007-11-04 17:55 .wapi
drwxr-xr-x 4 aldaril aldaril 4096 2007-11-01 19:48 .wine
-rw-r--r-- 1 aldaril aldaril 45 2007-10-28 19:10 .wxcas
-rw------- 1 aldaril aldaril 52 2007-11-11 02:47 .Xauthority
drwxr-xr-x 3 aldaril aldaril 4096 2007-11-11 04:47 .xine
drwxr-xr-x 4 aldaril aldaril 4096 2007-10-27 07:54 .xmms
-rw------- 1 aldaril aldaril 246803 2007-11-11 07:39 .xsession-errors
-rw------- 1 aldaril aldaril 0 2007-10-31 07:06 .xsession-errors-:1
Y por último
ls -l /home Aquí sale:
total 4
drwxr-xr-x 60 aldaril aldaril 4096 2007-11-11 07:24 aldaril
Por lo que veo sólo root puede acceder a .config, pero, ¿no se supone , como ya comentaron aquí, que en Kubuntu no hay root?
Saludos y gracias.
Edito:
Al final entré con sudo en konqueror y cambié los permisos de la carpeta .config y ya puedo editarla. Sin embargo, me gustaría que me comentasen si es inapropiado lo que hice. Simplemente cambié el propietario root por mi usuario, tal como están las demás carpetas de home/mi usuario, dejando los permisos de grupo y otros como prohibido.
Saludos.