This will make nautilus loose the burn:// capability, but it won't hold burned device opened.
Another problem, which I did report upstream is that devicekit or even kernel locks cdrom while mounted, but it should instead at least try to unmount the disk on button press.
So this is two bugs interealeved.
One is that nautilus keeps the cdrom device open (test it with fuser). This is fault of brasero, I will open a seperate bug about that.
As a workaround, rename
mv /usr/lib/ nautilus/ extensions- 2.0/libnautilus -brasero- extension. so /usr/lib/ nautilus/ extensions- 2.0/libnautilus -brasero- extension. s_o
This will make nautilus loose the burn:// capability, but it won't hold burned device opened.
Another problem, which I did report upstream is that devicekit or even kernel locks cdrom while mounted, but it should instead at least try to unmount the disk on button press.