Thanks for the responses from both Lightning UK and lfcrule1972 which have been very helpful. Think ultimately I will purchase a new burner, probably the Pioneer DVR-112, but have some additional information that hopefully will be of help.
Tried to close one of my coasters manually and had the folllowing error code,
Lightning UK responded in a another thread Power Calibration Error that,
`Power Calibration Errors are caused by firmware that doesn't fully support the media you're using.
Look for a firmware update or use different discs that the drive does support.'
The original log for the problem disc mentioned above,
I 18:56:25 ImgBurn Version 2.1.0.0 started!
I 18:56:25 Microsoft Windows XP Home Edition (5.1, Build 2600 : Service Pack 2)
W 18:56:25 AnyDVD can interfere with ImgBurn's ability to verify accurately, please ensure it's disabled!
I 18:56:25 Initialising SPTI...
I 18:56:25 Searching for SCSI / ATAPI devices...
I 18:56:25 Found 1 CD-RW, 1 DVD-ROM and 1 DVD?RW!
I 18:56:28 Operation Started!
I 18:56:28 Source File: D:\Film0 DVD\Taxi Driver (1976)\TAXI_DRIVER.MDS
I 18:56:28 Source File Sectors: 3,884,576 (MODE1/2048)
I 18:56:28 Source File Size: 7,955,611,648 bytes
I 18:56:28 Source File Volume Identifier: TAXI_DRIVER
I 18:56:28 Source File Implementation Identifier: SONY DVD Video
I 18:56:28 Source File File System(s): ISO9660, UDF (1.02)
I 18:56:28 Destination Device: [3:0:0] _NEC DVD_RW ND-3520AW 3.07 (E:) (ATA)
I 18:56:28 Destination Media Type: DVD+R DL (Disc ID: MKM-001-00) (Speeds: 2.4x, 4x)
I 18:56:28 Destination Media Sectors: 4,173,824
I 18:56:28 Write Mode: DVD
I 18:56:28 Write Type: DAO
I 18:56:28 Write Speed: 2.4x
I 18:56:28 Link Size: Auto
I 18:56:28 Test Mode: No
I 18:56:28 BURN-Proof: Enabled
I 18:56:28 Optimal L0 Data Zone Capacity: 1,976,960
I 18:56:28 Optimal L0 Data Zone Method: Copied From Original Disc
I 18:57:11 Filling Buffer...
I 18:57:11 Writing LeadIn...
I 18:57:13 Writing Image...
I 18:57:13 Writing Layer 0... (LBA: 0 - 1976959)
I 19:17:01 Writing Layer 1... (LBA: 1976960 - 3884575)
I 19:36:09 Synchronising Cache...
I 19:36:10 Closing Track...
I 19:36:23 Finalising Disc...
W 19:36:28 Potential 'WaitImmediateIO' Deferred Error - (0/2) - Write Error
W 19:41:47 Potential 'WaitImmediateIO' Deferred Error - (0/2) - Write Error
E 19:41:49 Finalise Disc Failed! - Reason: Write Error
I 19:41:49 Image MD5: ca88b17897df495fa2d6dea92a88acb3
I 19:41:49 Operation Successfully Completed! - Duration: 00:45:20
I 19:41:49 Average Write Rate: 3,327 KB/s (2.4x) - Maximum Write Rate: 3,674 KB/s (2.7x)
I 19:41:49 Cycling Tray before Verify...
I 19:42:11 Device Ready!
I 19:42:16 Operation Started!
I 19:42:16 Source Device: [3:0:0] _NEC DVD_RW ND-3520AW 3.07 (E:) (ATA)
I 19:42:16 Source Media Type: DVD+R DL (Book Type: DVD+R DL) (Disc ID: MKM-001-00) (Speeds: 2.4x, 4x)
I 19:42:16 Image File: D:\Film0 DVD\Taxi Driver (1976)\TAXI_DRIVER.MDS
I 19:42:16 Image File Sectors: 3,884,576 (MODE1/2048)
I 19:42:16 Image File Size: 7,955,611,648 bytes
I 19:42:16 Image File Volume Identifier: TAXI_DRIVER
I 19:42:16 Image File Implementation Identifier: SONY DVD Video
I 19:42:16 Image File File System(s): ISO9660, UDF (1.02)
I 19:42:16 Verifying Sectors...
E 19:42:28 Failed to read Sector 32 - Unrecovered Read Error
E 19:42:28 Failed to Verify Sectors!
E 19:42:28 Operation Failed! - Duration: 00:00:12
I 19:42:28 Average Verify Rate: 5 KB/s (0.0x) - Maximum Verify Rate: 5 KB/s (0.0x)
I 19:42:30 Close Request Acknowledged
I 19:42:30 Closing Down...
I 19:42:45 Shutting down SPTI...
I 19:42:45 ImgBurn closed!
I have burnt the MKM-001-00 discs successfully but overall it has been hit or miss. Hopefully this additional information is of use. The problem may be connected to this error listed in the system log in event viewer at the same time the the burn occurred (multiple entries),
The device, \Device\CdRom0, has a bad block.