dvd configuration error

[Dave]

Hello,
    I've gota 6.2 box with a dvd writer in it. I'm having what i believe is 
a configuration error on my part, which is driving me crazy.
    I've got the device installed, it shows up in dmesg as /dev/acd1. I have 
an fstab entry for it as:

/dev/acd1 /cdrom1 cd9660 ro,noauto 0 0

i've tried commenting this line out with the below and it doesn't matter. In 
loader.conf i have:

hw.ata.atapi_dma="1"

i can mount a dvdrw with either:
mount /cdrom1
or
mount /dev/acd1 /cdrom1

and in either case it works fine. I can read dvdrw's with no problem. I'm 
using dvd+rw-tools 7.0 from ports.
    I'm trying to blank a dvdrw so i can rewrite to it. I'm using 
dvd+rw-format /dev/acd1 i've also tried dvd+rw-mediainfo /dev/acd1 and in 
both cases i'm getting the error:

/dev/acd1: unable to open: inappropriate ioctl for device

    Suggestions appreciated.
Thanks.
Dave.