DMA on CD Burners

[Jason Martens <me@jasonmartens.com>]

Does anyone know why I can't set DMA on my CD Burners?  It makes burning 
CD's very slooooooow.  When I try to set it with hdparm, I get the 
following error:

morpheus:~# hdparm -d1 /dev/hdb

/dev/hdb:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Operation not permitted
 using_dma    =  0 (off)


I've tried it on two seperate drives, with the same result:
hda: SONY DVD RW DW-U10A, ATAPI CD/DVD-ROM drive
hdb: TSST CD-RW/DVD-ROM TSH492B, ATAPI CD/DVD-ROM drive

Jason Martens