Is your CD/DVD Burning too slow? Does it make your system hang? Maybe you need to enable DMA !!
I bought a DVD writer, an LG model, and I noticed that burning was slower than usual and it was making my system hang.
To check whether DMA was enabled, I did:
sudo cat /proc/ide/hdd/
The last line was something like this:
using_dma 0 0 1 rw
Notice that the value in the first column is zero, which means that DMA is not enabled.
Then I ran the command:
sudo hdparm -d1 /dev/hdd
And Tada !! CD burning doubled in speed, and no more hanging. cool, eh ?
Edit: Everytime you reboot, DMA will be disabled, so you have to take appropriate steps to make sure that DMA is enabled on boot. Ubuntu users can follow this guide.