Thanks... chose that option (then downloaded a trial version of DVD Info Pro) then tried the option again. I couldn't see any info on filters, but I only had a quick look. I'll search again (it's on another PC). In the mean time here's the contents of one of the IBG files... could this help me?
IBGD
;PLEASE READ THE LICENSE AGREEMENT BEFORE USING THIS FILE
;BY USING THIS FILE, YOU AGREE TO BE BOUND BY ITS TERMS
[sTART_CONFIGURATION]
IBGD_VERSION=2
DATE=29/08/2010 12:59:21
SAMPLE_RATE=100
DEVICE=[1:1:0] HL-DT-ST RW/DVD GCC-4480B 1.00 (D:) (ATA)
DEVICE_ADDRESS=1:1:0
DEVICE_MAKEMODEL=HL-DT-ST RW/DVD GCC-4480B
DEVICE_FIRMWAREVERSION=1.00
DEVICE_DRIVELETTER=D
DEVICE_BUSTYPE=ATA
MEDIA_TYPE=CD-R
MEDIA_BOOKTYPE=CD-R
MEDIA_ID=97m26s66f
MEDIA_TRACKPATH=PTP
MEDIA_SPEEDS=N/A
MEDIA_CAPACITY=359844
MEDIA_LAYER_BREAK=0
DATA_IMAGEFILE=C:\Temp\AudioRecording20100815.cue
DATA_SECTORS=29897
DATA_TYPE=AUDIO/2352
DATA_VOLUMEIDENTIFIER=
WRITE_TEST_MODE=False
WRITE_SPEED_SELECTED=MAX
WRITE_SPEED_START=14.40
WRITE_SPEED_END=16.27
WRITE_SPEED_AVERAGE=12.86
WRITE_SPEED_MAX=16.27
WRITE_TIME_TAKEN=82
[END_CONFIGURATION]
HRPC=True
[sTART_WRITE_GRAPH_VALUES]
18.18,999,99,0.00,0.00
7.20,1053,100,0.00,0.00
0.00,1053,100,0.00,0.00
0.00,1053,100,0.00,0.00
....numbers continue for a while....