cd burning with nautilus

[Martin Ericsson]

Hi.
I can't burn .iso-files from nautilus. It usually gives me the following 
error: "Please put a blank disc, with at least 638 MB free, into the 
drive." even if a use a fresh cd. Last time it accepted the CD but 
frooze during the initializing phase.

GnomeBaker burns the CD without problem but gives a couple of error 
messages. I don't know if I should care about them?

cdrecord: Operation not permitted. WARNING: Cannot set RR-scheduler
cdrecord: Permission denied. WARNING: Cannot set priority using 
setpriority().
cdrecord: WARNING: This causes a high risk for buffer underruns.
scsidev: '/dev/hdc'
devname: '/dev/hdc'
scsibus: -2 target: -2 lun: -2
Warning: Open by 'devname' is unintentional and not supported.


My CD-Writer is a HP Plus 9100. It's fstab entry is:
/dev/hdc        /media/cdrom0   udf,iso9660 ro,user,noauto  0       0

Regards,
Martin Ericsson