Thank you to everyone that replied.
The DVD burner did drop into PIO mode. Took a BIOS change to get it back to DMA.
It still took a long time to copy Fast Five. It would do 95% quickly, then slow down for hours on the last 5%.
I tried on a differnet PC and got read errors during the analysing of the disk. Took it back and exchanged. The new disk went fast.
Thanks again for the help