hdparm -d1: Operation not permitted

[Mark <markdrago@mail.com>]

I'm trying to turn on dma on my dvd drive so that when I play dvds the 
movie plays real smooth.  When I run 'hdparm -d1 /dev/dvd' I get this 
output:

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

I get the same output when I do 'hdparm -d1 /dev/hda':

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

Yes, I am running this as root.  The permissions on the drives are set 
as: rw-rw----, root is the owner and disk is the group.  I don't think 
it's a problem with the permissions, being that I'm running it as root. 
 Google was of little help, steering me to think that the support for 
my ide controller might not have been built into the kernel.  I am 
running an newer motherboard: abit at7 max.  It uses the kt333 chipset. 
 From what I understand it is a fairly popular via chipset.  I am also 
running the 2.4.18-bf2.4 kernel.  Anyone have any ideas why I would not 
be able to enable dma on any of my drives?  I know the drives can do it 
b/c dma works in mandrake.

--Mark.