No puedo borrar CD-RW con K3B

[Santiago David Delgado Llopis]

Hola a tod en s:
  Tengo un pequeño problemilla con K3B. Resulta que quería borrar un
CD-RW y no me deja. Entiendo que es un problema de permisos, pero no
sé cómo solucionarlo. Adjunto el log que me ha devuelto K3B.
  ¿Alguien me puede echar una mano?

  Muchas gracias de antemano.

System
-----------------------
K3b Version: 0.12.17

KDE Version: 3.5.5
QT Version:  3.3.6
Kernel:      2.6.17-11-generic
Devices
-----------------------
_NEC DVD+-RW ND-6650A 1.42 (/dev/scd0, /dev/sg1) at /media/cdrom0
[CD-R; CD-RW; CD-ROM; DVD-ROM; DVD-R; DVD-RW; DVD-R DL; DVD+R; DVD+RW;
DVD+R DL] [DVD-ROM; DVD-R Secuencial; DVD-R Doble capa secuencial;
DVD-RW sobreescritura restringida; DVD-RW Secuencial; DVD+RW; DVD+R;
DVD+R doble capa; CD-ROM; CD-R; CD-RW] [SAO; TAO; En bruto; SAO/R96R;
RAW/R96R; Sobreescritura restringida]

Used versions
-----------------------
cdrecord: 2.1.1a03

cdrecord command:
-----------------------
/usr/bin/X11/cdrecord.mmap -v gracetime=2 dev=1,0,0 speed=10 -tao
driveropts=burnfree -eject blank=fast -force

cdrecord
-----------------------
/usr/bin/X11/cdrecord: Warning: Running on Linux-2.6.17-11-generic

/usr/bin/X11/cdrecord: There are unsettled issues with Linux-2.5 and newer.
/usr/bin/X11/cdrecord: If you have unexpected problems, please try
Linux-2.4 or Solaris.
scsidev: '1,0,0'
scsibus: 1 target: 0 lun: 0
Error trying to open /dev/sg0 exclusively (Permission denied)...
retrying in 1 second.
Error trying to open /dev/sg0 exclusively (Permission denied)...
retrying in 1 second.
Error trying to open /dev/sg0 exclusively (Permission denied)...
retrying in 1 second.
Error trying to open /dev/sg0 exclusively (Permission denied)...
retrying in 1 second.
Error trying to open /dev/sg0 exclusively (Permission denied)...
retrying in 1 second.
Error trying to open /dev/sg0 exclusively (Permission denied)...
retrying in 1 second.
Error trying to open /dev/sg0 exclusively (Permission denied)...
retrying in 1 second.
Error trying to open /dev/sg0 exclusively (Permission denied)...
retrying in 1 second.
Error trying to open /dev/sg0 exclusively (Permission denied)...
retrying in 1 second.
Error trying to open /dev/sg0 exclusively (Permission denied)...
retrying in 1 second.
/usr/bin/X11/cdrecord: Permission denied. Cannot open '/dev/sg0'.
Cannot open SCSI driver.
/usr/bin/X11/cdrecord: For possible targets try 'cdrecord -scanbus'.
Make sure you are root.
/usr/bin/X11/cdrecord: For possible transport specifiers try 'cdrecord
dev=help'.
/usr/bin/X11/cdrecord:
/usr/bin/X11/cdrecord: For more information, install the cdrtools-doc
/usr/bin/X11/cdrecord: package and read
/usr/share/doc/cdrecord/README.ATAPI.setup .
Cdrecord-Clone 2.01.01a03 (i686-pc-linux-gnu) Copyright (C) 1995-2005
Joerg Schilling
NOTE: this version of cdrecord is an inofficial (modified) release of cdrecord
      and thus may have bugs that are not present in the original version.
      Please send bug reports and support requests to
<cdrtools en packages.debian.org>.
      The original author should not be bothered with problems of this version.
TOC Type: 1 = CD-ROM