Hmm, using "Nero Info Tool" I can see that the disc is "Blank DVD+R" and Capacity "n/a"
If I look into "Drive" I can see that under "Supported write features" all of the various disc types are supported by tick boxes except DVD+R and DVD+RW and I am unable to place a tick in the box. I guess therefore that I cannot do anything to make the drive accept DVD+R discs!