I'm having intermittent problems with DVD burning with k3b.
I try to burn a DVD at 16x (which is what it automatically determines is the correct speed)...somtimes it workes somtimes it failes giving me this error:

OPC failed. Please try writing speed 1x.
Fatal error at startup: Input/output error

Here is the debugging output:

System
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K3b Version: 0.12.12

KDE Version: 3.5.1
QT Version: 3.3.5
Kernel: 2.6.12-1-k7
Devices
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_NEC DVD_RW ND-3520A 1.04 (/dev/hdd, ) at /media/cdrom0 [CD-R; CD-RW; CD-ROM; DVD-ROM; DVD-R; DVD-RW; DVD+R; DVD+RW; DVD+R DL] [DVD-ROM; DVD-R Sequential; DVD-RW Restricted Overwrite; DVD-RW Sequential; DVD+RW; DVD+R; DVD+R Double Layer; CD-ROM; CD-R; CD-RW] [SAO; TAO; RAW; SAO/R96P; SAO/R96R; RAW/R16; RAW/R96P; RAW/R96R; Restricted Overwrite]

HL-DT-ST CD-ROM GCR-8481B 1.06 (/dev/hdc, ) at /media/cdrom1 [CD-ROM] [CD-ROM] [None]
Used versions
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growisofs: 6.1

growisofs
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Executing 'builtin_dd if=/home/qcoder/k3b_image.iso of=/dev/hdd obs=32k seek=0'
:-[ PERFORM OPC failed with SK=3h/ASC=73h/ACQ=03h]: Input/output error

growisofs command:
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/usr/bin/growisofs -Z /dev/hdd=/home/qcoder/k3b_image.iso -use-the-force-luke=notray -use-the-force-luke=tty -use-the-force-luke=tracksize:2247745 -dvd-compat -speed=16 -use-the-force-luke=bufsize:40m

I'm using Memorex DVD-R DVDs that are rated for 16x
also After it fails I am able to burn it at a speed of 2x....

So is this a hardware/software problem or is it a problem with the media?
Any help would be appreciated.

Thanks.

have you tried running k3b as root from the run menu type:
kdesu k3b

then try it again

by default normal users are not given permission to use the cd/dvd writer

I tried it......it seemed to work once.....but then when I tried to burn another one
It failed with the same error :-(