Confusing "Success" and "Error while burning. "TSSTcorp CDDVDW SE-S084C" cannot be unlocked"

Binary package hint: nautilus-cd-burner

While trying to burn a DVD, I get a "Success" message when it's done, with another window on it indicating Error while burning. "TSSTcorp CDDVDW SE-S084C" cannot be unlocked.

All files seemed to be OK on the DVD and I checked the MD5 sum of a bigger (>2GB) file succesfully:

Here is the file listing, attached are the log and screenshot corresponding to this confusing error message.

ubuntu@ubuntu-laptop:/media/hp-tx1220ca-recovery_2of2$ ls -lah
total 2.3G
dr-xr-xr-x 2 ubuntu ubuntu 2.0K 2010-06-14 09:36 .
drwxr-xr-x 4 root root 4.0K 2010-06-14 09:44 ..
-r--r--r-- 1 ubuntu ubuntu 512 2010-05-31 10:59 backup-sda.mbr
-r--r--r-- 1 ubuntu ubuntu 249 2010-05-31 11:00 backup-sda.sf
-r--r--r-- 1 ubuntu ubuntu 277 2010-06-14 09:36 .checksum.md5
-r--r--r-- 1 ubuntu ubuntu 2.3G 2010-05-31 10:41 hp-tx1220ca-recovery.001
-r--r--r-- 1 ubuntu ubuntu 119 2010-06-01 15:43 hp-tx1220ca-recovery-md5sums.txt
-r--r--r-- 1 ubuntu ubuntu 737 2010-06-01 13:47 RECOVERY-README.txt

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: nautilus-cd-burner (not installed)
ProcVersionSignature: Ubuntu 2.6.32-22.33-generic 2.6.32.11+drm33.2
Uname: Linux 2.6.32-22-generic i686
NonfreeKernelModules: wl
Architecture: i386
Date: Mon Jun 14 09:46:28 2010
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Beta i386 (20100406.1)
ProcEnviron:
 LANG=en_CA.utf8
 SHELL=/bin/bash
SourcePackage: nautilus-cd-burner