I think burning had got about 50% though was not actually watching.
I re-started PowerDirector and tried again with the same project; previous disc had enough on it to be unusable but fresh disc resulted in a succesful burn
A dodgy disc perhaps?
I use ones from Tesco - DVD+R 8x 4.7gb; usually OK when I have used them previously with PowerProducer v3. Director Suite 365
AMD FX-8320 3.50 GHz Eight-Core
Samsung SSD 850 EVO 250gb (OS)
Seagate 2TB SATA-III Hybrid 7200RPM Hard Drive (Data)
Toshiba 4TB SATA-III Hard drive (Archive)
24GB Memory
Nvidia GeForce GTX 650 2gb
Microsoft® Windows 10 (64-bit)