Two possibilities:
1. Something is interfering with Nero identifying the media (post the Nerohistory log, after removing your serial number wherever it appears)
2. 1.04 firmware is old (up to 1.14 now) - maybe the drive doesn't recognise the media at 1.04 - is it ok with normal DVD +R or -R media.
Try DVDshrink / recode or whatever, and squeeze it down to a single layer burn size - you may find the quality good enough to save the expensive DL media for when you really need it.