Problems burning DVD-RW

[christian]

Hi!

Every once a while I'd like to burn a DVD-RW. It works as long as I'm 
using fresh (blank) DVD-RW media. But if I want to overwrite a non-blank 
one then I get the following output:

[root at hugo ~]# cdrecord -v dev=4,0,0 -dao ~cg/myimage.iso
Cdrecord-ProDVD-ProBD-Clone 3.00 (amd64-unknown-freebsd9.1) Copyright 
(C) 1995-2010 Jörg Schilling
TOC Type: 1 = CD-ROM
scsidev: '4,0,0'
scsibus: 4 target: 0 lun: 0
Using libscg version 'schily-0.9'.
SCSI buffer size: 65536
atapi: 0
Device type    : Removable CD-ROM
Version        : 0
Response Format: 2
Capabilities :
Vendor_info    : 'TSSTcorp'
Identifikation : 'CDDVDW SH-S223C '
Revision       : 'SB07'
Device seems to be: Generic mmc2 DVD-R/DVD-RW/DVD-RAM.
Current: DVD-RW restricted overwrite
Profile: DVD+R/DL
Profile: DVD+R
Profile: DVD+RW
Profile: DVD-R/DL layer jump recording
Profile: DVD-R/DL sequential recording
Profile: DVD-RW sequential recording
Profile: DVD-RW restricted overwrite (current)
Profile: DVD-RAM
Profile: DVD-R sequential recording
Profile: DVD-ROM
Profile: CD-RW
Profile: CD-R
Profile: CD-ROM
Profile: Removable Disk
Using generic SCSI-3/mmc-2 DVD-R/DVD-RW/DVD-RAM driver (mmc_dvd).
Driver flags   : NO-CD DVD MMC-3 SWABAUDIO BURNFREE
Supported modes: PACKET SAO LAYER_JUMP
Drive buf size : 1048576 = 1024 KB
cdrecord: Warning: Cannot read drive buffer.
cdrecord: Warning: The DMA speed test has been skipped.
FIFO size      : 4194304 = 4096 KB
Track 01: data  1028 MB
Total size:     1028 MB = 526760 sectors
Current Secsize: 2048
Trying to clear drive status.
cdrecord: Drive needs to reload the media to return to proper status.
WARNING: Phys disk size 2297888 differs from rzone size 0! Prerecorded disk?
WARNING: Phys start: 196608 Phys end 2494495
WARNING: Drive returns zero media size. Using media size from ADIP.
Blocks total: 2297888 Blocks current: 2297888 Blocks remaining: 1771128
Starting to write CD/DVD/BD at speed 2 in real SAO mode for single session.
Last chance to quit, starting real write    0 seconds. Operation starts.
Waiting for reader process to fill input buffer ... input buffer ready.
BURN-Free is ON.
Turning BURN-Free off
cdrecord: Input/output error. reserve_track_rzone: scsi sendcmd: 
retryable error
CDB:  53 00 00 00 00 00 08 09 A8 00
status: 0x2 (CHECK CONDITION)
Sense Bytes: 70 00 05 00 00 00 00 0A 00 00 00 00 72 05 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00
Sense Key: 0x5 Illegal Request, Segment 0
Sense Code: 0x72 Qual 0x05 (no more track reservations allowed) Fru 0x0
Sense flags: Blk 0 (not valid)
cmd finished after 0.002s timeout 200s
cdrecord: Cannot open next track.
Writing  time:    0.023s
Average write speed 999.0x.
Fixating...
Fixating time:    0.001s
cdrecord: fifo had 64 puts and 0 gets.
cdrecord: fifo was 0 times empty and 0 times full, min fill was 100%.


Dmesg tells me:

cd0 at ahcich3 bus 0 scbus4 target 0 lun 0
cd0: <TSSTcorp CDDVDW SH-S223C SB07> Removable CD-ROM SCSI-0 device
cd0: Serial Number R4136GFZC30006
cd0: 150.000MB/s transfers (SATA 1.x, UDMA5, ATAPI 12bytes, PIO 8192bytes)
cd0: cd present [2297888 x 2048 byte records]

What can I do to get this working? BTW, I'm using 9.1 stable (rev. 274731).

Thanks for your help,
Christian.