109. 157 drive not found

Just burned two bootable partitions in two DVD+R 8x and 4x respectively with Alcohol and I got the news that the drive does not recognise the discs or the files burned for that matter
Alcohol reported as a good burn so I decided for a DVD-R format disc and that was recognised. However I previously burned a DVD+R of the same format (bootable) and did not have a problem and it is recognised by the drive
So cananyone help me here?
What is the problem here? Thanks