求助：dvd 刻不了，

melon

我的是fc5，gnome下有个gui界面的xcdroast  可以刻cd－r，但刻不了DVD－R，Disk image size too large (max. 1 GB in demo mode).
我用prodvd命令行刻时也一样， 具体见下面。这话是什么意思啊？
如果只刻300M就没这错误，不过也不行，听光驱声音响了一会又不响了，再看这时系统已经死机。
有谁知道吗？难道我的DVD-RW就没用武之地了？
[root@localhost download]# cdrecord.prodvd -ignsize -sao  dvd.iso dev=0,0,0
Cdrecord-ProDVD-Clone 2.01.01b03 (i686-pc-linux-gnu) Copyright (C) 1995-2006 J�rg Schilling
Unlocked features:
Limited  features:
cdrecord.prodvd: Warning: Running on Linux-2.6.15-1.2054_FC5
cdrecord.prodvd: There are unsettled issues with Linux-2.5 and newer.
cdrecord.prodvd: If you have unexpected problems, please try Linux-2.4 or Solaris.
scsidev: '0,0,0'
scsibus: 0 target: 0 lun: 0
Linux sg driver version: 3.5.33
Using libscg version 'schily-0.8'.
Device type    : Removable CD-ROM
Version        : 0
Response Format: 1
Vendor_info    : 'BENQ    '
Identifikation : 'DVD DD DW1650   '
Revision       : 'BCHC'
Device seems to be: Generic mmc2 DVD-R/DVD-RW.
cdrecord.prodvd: This version of cdrecord limits DVD-R/DVD-RW support to -dummy or 1 GB real.
cdrecord.prodvd: If you need full DVD-R/DVD-RW support, ask the Author for cdrecord-ProDVD.
cdrecord.prodvd: Free test versions and free keys for personal use are at ftp://ftp.berlios.de/pub/cdrecord/ProDVD/
Using generic SCSI-3/mmc-3 DVD+R driver (mmc_dvdplusr).
Driver flags   : DVD MMC-3 SWABAUDIO BURNFREE
Supported modes: PACKET SAO
cdrecord.prodvd: Disk image size too large (max. 1 GB in demo mode).
[root@localhost download]#