Because my laptop's combo drive was giving trouble and hasn't burnt a proper cd for months, I bought an LG external dvd writer this weekend. The LG GSA-5163d can handle all formats, - + Ram and + dual layer, and has USB2 and Firewire. Great, right? Almost. I tested it in Ubuntu and saw it mounted disks with data on it fine, and I burned a DVD in windows (happened to be on at the time), all worked great. Until I tried to burn something in Ubuntu....

First of all, I was used to nautilus showing "Blank Disk" or something to that effect in the browser sidebar. It didn't. If I turned the blank disk command back on in the 'Removable media' settings it would show the CD/DVD creator but no disk. If I tried to burn it failed, giving inconclusive error messages.
Dmesg just said: "cdrom: This disc doesn't have any tracks I recognize!" when I inserted a blank disk but I think that's normal.

I finally got it to mount blank disks like I was used to, as well as audio cds which it didn't want to show either (which turns it is pretty useless because of course it doesn't have an audio cable), by making an entry for the drive in /etc/fstab:

/dev/scd0 /media/cdromExt udf,iso9660 ro,user,noauto 0 0

Now when I put in a blank disk, it showed up in Nautilus. Ok, step forward, but burning still didn't work. In dmesg line after line appeared saying "SCSI error : <3 0 0 0> return code = 0x70000"
This was the key. This time I found a thread that described the same type of problem. Because this concerned a different but similar LG I didn't find it before. Searching for super multi dvd rewriter would have done it but it didn't enter my mind.. I only tried it using the type number so far. Anyway, this message had the answer that solved the problem for me: use cdrecord with -ts=32768. It worked! I did also have to use -driveropts=burnfree because I got an error telling me to try that but after that, it burned the CD within minutes. Yay!

The complete cdrecord command I used:

cdrecord --dev=/dev/scd0 -ts=32768 -driveropts=burnfree file.iso
Where /dev/scd0 is the device name it has in my case, check the device manager to see what /dev it is.