That bug has been opened on https://launchpad.net/distros/ubuntu/+source/nautilus-cd-burner/+bug/49470

"1. Put in plank DVD-R, start CD/DVD creator, put files in, burn them at DVD speed of your choice
2. Take out freshly burned DVD, put in blank CD-R
3. For example, this time choose ISO to burn. So, pick up some iso file, ubuntu-6.06-desktop-i386.iso for example, choose in right button menu "Burn..." and on with it
4. Expierence DVD speeds to be given (x152, x82, etc.), not CD-R speeds (from x2 to x52)
5. For me, it give burning error when I try to burn disc, using DVD speeds lower one, x31

It wasn't problem some time ago, so it came up recently, with last updates before final 6.06 LTS release
...
> Thanks for your bug. Do you close the dialog before trying to burn the iso? Does it happen only if you record a DVD or can you get it also just by starting the dialog and cancelling the action? What "/usr/share/nautilus-cd-burner/list_cddrives" write when you have the DVD or the CD to the drive?
...


Answer to your questions:
1. Yes, I try to close and open it again before trying to burn iso. Speeds, however, doesn't change;
2. Now I testing it and it is such way:
  + Restart system;
  + With no disc choose to burn ISO;
  + CD speeds appears;
  + Insert DVD, close "would want to make DVD" dialog, choose to burn ISO;
  + Still CD speeds appears;
3. /usr/share/nautilus-cd-burner/list_cddrives gives me such info:
+ with DVD
Drive:
  name: TSSTcorpCD/DVDW SH-W162C
  device: /dev/hda
  door: closed
  type: CD-R, CD-RW, DVD-RW, DVD+R, DVD+R DL, DVD+RW, CD, DVD
  is mounted: FALSE
  max read speed: 48
  max write speed: 48
  write speeds: 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
Media:
  label: ''
  type: DVD-R, or DVD-RAM (blank)
  is writable: TRUE
  size: 4489.25 MiB

+ with CD
Drive:
  name: TSSTcorpCD/DVDW SH-W162C
  device: /dev/hda
  door: closed
  type: CD-R, CD-RW, DVD-RW, DVD+R, DVD+R DL, DVD+RW, CD, DVD
  is mounted: FALSE
  max read speed: 48
  max write speed: 48
  write speeds: 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
Media:
  label: ''
  type: CD-R (blank)
  is writable: TRUE
  size: 701.00 MiB approx. or 80 mins 0 secs

Additionally, row from dmesg:
[4294672.900000] hda: TSSTcorpCD/DVDW SH-W162C, ATAPI CD/DVD-ROM drive



http://hwdb.ubuntu.com/?xml=b684ecfe930c5c4f98ebda14a86393b3

My hardware profile."