Are you sure that that is all you get out of:
dmesg|grep sr

Because that don't make any sence. The wery first lines should tell you what device it is.

from my box
[code]
hl@sid:~$ dmesg |grep sr
sr0: scsi3-mmc drive: 6x/48x cd/rw xa/form2 cdda tray
Attached scsi CD-ROM sr0 at scsi0, channel 0, id 0, lun 0
sr1: scsi3-mmc drive: 32x/32x writer cd/rw xa/form2 cdda tray
Attached scsi CD-ROM sr1 at scsi1, channel 0, id 0, lun 0
hl@sid:~$
[/code/]

Try this:
dmesg|grep sr|less