Dammit - I knew that wasn't the exact error message but it was so late and I was so tired! It was definitely something to do with write speed and I think the first word began with 're .....' if that helps. Sorry I am being so vague.
I can't replicate this error until I get home and I really don't want to go through the whole DVDFLick process again as this takes just over an hour. I assume I can just open ImgBurn now that the files have been created and just try and burn the ISO file?
This is very similar (if not exact) to the log file I had:
I 21:45:25 ImgBurn Version 2.3.2.0 started!
I 21:45:25 Microsoft Windows XP Home Edition (5.1, Build 2600 : Service Pack 2)
I 21:45:25 Total Physical Memory: 457,456 KB - Available: 270,840 KB
I 21:45:25 Initialising SPTI...
I 21:45:25 Searching for SCSI / ATAPI devices...
I 21:45:25 Found 1 DVD±RW! 1 CD ROM!
Again, sorry if I am being vague, but I can't do this from work :-( Thanks for your help