Hm, I thought that Nero 6 didn't work for burning stuff. At least that was the case a year ago, last time I was paying attention to the DC homebrew scene.
Have you been using Nero 6 all along and with these same settings?
I don't think I can give you any help, though, really.
But if you're burning Dream Hakker, you should know that you can put a background image on the disc, too, to make everything look smuch nicer. It has to be a JPEG and go in DREAMHAKKER/BKG/ You can even have multiple images and switch between them using the third button on the title bar. Dream Hakker's a kick ass app.
Here's the background image I use:
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