In my VB.net 2005 application I am using nero.com to burn dvds.

It worked perfectly till yesterday (it burned about 20 discs) but now it can't burn!!
Nothing has changed (no new program installed and configuration is the same as yesterday).

My log is:

Reading directories
Creating directories
Checking discs
Can only write at 16x (22.160 KB/s) instead of 32.1x (44.320 KB/s) to current disc.
Writing to cache
Caching of files started
Caching of files completed
Writing to disc
Burn process started at 16x (22.160 KB/s)
Invalid field in command
D: HL-DT-ST DVDRAM GSA-4167B
Could not perform start of Disc-at-once
Burn process failed at 16x (22.160 KB/s)
****-****-****-****-****-****-****

Windows XP 5.1
IA32
WinAspi: -
ahead WinASPI: File 'C:\Programmi\Nero\Nero 7\Core\Wnaspi32.dll': Ver=2.0.1.74, size=164112 bytes, created 02/11/2004 13.54.32

NT-SPTI used
Nero API version: 7.5.7.0
Using interface version: 7.0.5.6
Installed in: C:\Programmi\Nero\Nero 7\Core\
Application: Nero - Burning Rom\nero
Internal Version: 7, 5, 7, 0

Recorder: Version: DL12 - HA 1 TA 0 - 7.5.7.0
Adapter driver: HA 1
Drive buffer : 2048kB
Bus Type : default (0) -> ATAPI, detected: ?

=== Scsi-Device-Map ===
CdRomPeripheral : HL-DT-ST DVDRAM GSA-4167B atapi Port 0 ID 0 DMA: On
DiskPeripheral : SAMSUNG HD400LD atapi Port 0 ID 1 DMA: On
DiskPeripheral : SAMSUNG HD400LJ atapi Port 1 ID 0 DMA: On

=== CDRom-Device-Map ===
HL-DT-ST DVDRAM GSA-4167B D: CDRom0
=======================

AutoRun : 1
Excluded drive IDs:
WriteBufferSize: 83886080 (0) Byte
BUFE : 0
Physical memory : 1023MB (1047596kB)
Free physical memory: 699MB (716344kB)
Memory in use : 31 %
Uncached PFiles: 0x0
Use Inquiry : 1
Global Bus Type: default (0)
Check supported media : Disabled (0)

1.3.2007
NeroAPI
18.24.31 #1 Text 0 File SCSIPassThrough.cpp, Line 583
LockMCN - completed sucessfully for IOCTL_STORAGE_MCN_CONTROL

18.24.31 #2 Text 0 File AudioCompilationImpl.cpp, Line 838
DRM: StartDrmRecording(RealRec:1, ImageRec:0, Copies:1)
DRM: Beginning burn process.

18.24.31 #3 ISO9660GEN -11 File Geniso.cpp, Line 3313
First writeable address = 0 (0x00000000)

18.24.31 #4 Text 0 File Burncd.cpp, Line 3435
Turn on Disc-At-Once, using DVD media

18.24.31 #5 Text 0 File DlgWaitCD.cpp, Line 301
Last possible write address on media: 2298495 (510:46.45, 4489MB)
Last address to be written: 2297999 (510:39.74, 4488MB)

18.24.31 #6 Text 0 File DlgWaitCD.cpp, Line 313
Write in overburning mode: NO

18.24.31 #7 Text 0 File DlgWaitCD.cpp, Line 2863
Recorder: HL-DT-ST DVDRAM GSA-4167B, Media type: DVD-R
Disc Manufacturer: MCC 03 - RG20
Disc Application Code: 64, Disc Physical Code: 193

18.24.31 #8 Text 0 File DlgWaitCD.cpp, Line 485
>>> Protocol of DlgWaitCD activities: <<<
=========================================

18.24.31 #9 Text 0 File ThreadedTransferInterface.cpp, Line 820
Setup items (after recorder preparation)
0: TRM_DATA_MODE1 ()
2 indices, index0 (150) not provided
original disc pos #0 + 2298000 (2298000) = #2298000/510:40.0
relocatable, disc pos for caching/writing not required/ required, no patch infos
-> TRM_DATA_MODE1, 2048, config 0, wanted index0 0 blocks, length 2298000 blocks [Main]
--------------------------------------------------------------

18.24.31 #10 Text 0 File Burncd.cpp, Line 4023
Can only write at 16x (22.160 KB/s) instead of 32.1x (44.320 KB/s) to current disc.

18.24.31 #11 Text 0 File ThreadedTransferInterface.cpp, Line 1033
Prepare recorder [HL-DT-ST DVDRAM GSA-4167B] for write in CUE-sheet-DAO
DAO infos:
==========
MCN: ""
TOCType: 0x00; Session Closed, disc fixated
Tracks 1 to 1: Idx 0 Idx 1 Next Trk
1: TRM_DATA_MODE1, 2048/0x00, FilePos 0 0 4706304000, ISRC ""
DAO layout:
===========
___Start_|____Track_|_Idx_|_CtrlAdr_|_____Size_|______NWA_|_RecDep__________
0 | lead-in | 0 | 0x41 | 0 | 0 | 0x00
0 | 1 | 0 | 0x41 | 2298000 | 0 | 0x00
0 | 1 | 1 | 0x41 | 2298000 | 0 | 0x00
2298000 | lead-out | 1 | 0x41 | 0 | 0 | 0x00

18.24.31 #12 Text 0 File SCSIPassThrough.cpp, Line 41
SPTILockVolume - completed successfully for FCTL_LOCK_VOLUME

18.24.31 #13 Phase 24 File APIProgress.cpp, Line 282
Caching of files started

18.24.31 #14 Text 0 File Burncd.cpp, Line 4262
Cache writing successful.

18.24.31 #15 Phase 25 File APIProgress.cpp, Line 282
Caching of files completed

18.24.31 #16 Phase 36 File APIProgress.cpp, Line 282
Burn process started at 16x (22.160 KB/s)

18.24.31 #17 Text 0 File ThreadedTransferInterface.cpp, Line 2730
Verifying disc position of item 0 (relocatable, disc pos, no patch infos, orig at #0): write at #0

18.24.31 #18 Text 0 File DVDR.cpp, Line 3026
Recording mode: Sequential Recording Mode for Multisession

18.24.32 #19 Text 0 File DVDR.cpp, Line 3182
Start write address at LBA 0
DVD high compatibility mode: No

18.24.32 #20 Text 0 File Cdrdrv.cpp, Line 9234
---- DVD Structure: Physical Format Information (00h) ----
Media Type: 0, Layer: 0, Address: 0 (0 h), AGID: 0; Length: 2050
Book Type: DVD-R (2), Part Version: 2.0x (5), Extended Part Version: 2.1 (33)
Disc Size: 120 mm, Maximum Rate: (F h)
Number of Layers: 1, Track Path: Parallel Track Path (PTP), Layer Type: recordable
Linear Density: 0,267 um/bit, Track Density: 0,74 um/track
Starting Physical Sector Number of Data Area: 30000 h (DVD-ROM, DVD-R/-RW, DVD+R/+RW)
End Physical Sector Number of Data Area: 26127F h
End Sector Number in Layer 0: 0 h (LBN: FFFD0000 h, 4193920 MB)
Data in Burst Cutting Area (BCA) does not exist
Start sector number of the current Border-Out: 2FE10 h
Start sector number of the next Border-In: 2FFA0 h
Media Specific [16..63]:
00 60 00 10 20 30 40 50 - 00 00 00 21 00 00 00 00 .`...0@P...!....
00 02 FE 10 00 02 FF A0 - 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 ................

18.24.32 #21 SPTI -1066 File SCSIPassThrough.cpp, Line 293
D: CdRom0: SCSIStatus(x02) WinError(0) NeroError(-1066)
Sense Key: 0x05 (KEY_ILLEGAL_REQUEST)
Sense Code: 0x24
Sense Qual: 0x00
CDB Data: 0x53 00 00 00 00 00 23 10 90 00 00 00
Sense Area: 0x70 00 05 00 00 00 00 10 53 00 00 0C 24 00 00 C0 00 05

18.24.32 #22 CDR -1066 File ThreadedTransferInterface.cpp, Line 1780
Invalid field in command
D: HL-DT-ST DVDRAM GSA-4167B

18.24.32 #23 TRANSFER -27 File ThreadedTransferInterface.cpp, Line 1780
Could not perform start of Disc-at-once

18.24.32 #24 Phase 38 File APIProgress.cpp, Line 282
Burn process failed at 16x (22.160 KB/s)

18.24.32 #25 Text 0 File AudioCompilationImpl.cpp, Line 863
DRM: DRM burn session terminated.

18.24.32 #26 Text 0 File AudioCompilationImpl.cpp, Line 892
DRM: Closing entire DRM handling. Bye.

18.24.32 #27 Text 0 File Cdrdrv.cpp, Line 10459
DriveLocker: UnLockVolume completed

18.24.32 #28 Text 0 File SCSIPassThrough.cpp, Line 583
UnLockMCN - completed sucessfully for IOCTL_STORAGE_MCN_CONTROL


Existing drivers:
File 'Drivers\CDRALW2K.SYS': Ver=8.0.0.212 , size=2560 bytes, created 26/01/2007 2.19.00
File 'Drivers\PXHELP20.SYS': Ver=3.00.43J, size=36624 bytes, created 26/01/2007 2.19.00 (Prassi/Veritas driver for win 2K)

Registry Keys:
HKLM\Software\Microsoft\Windows NT\CurrentVersion\WinLogon\AllocateCDROMs : 0 (Security Option)

Scrittura terminata con ERRORI (3)

--------------------

Any hint?

Can you help me please?

Thanks in advance!