I was using NERO this morning to try and create a dvd and it kept on asking me for a disc even though I tried three new discs. Not sure but at one point it said that it did not recognise a DVDRW but a CDR/RW. This is no good if I want to create a DVD.
I take it that you told it to burn to DVD+RW and not CD. I don't use Nero but in Pinacle I have to physically tick the type of medium I am burning to, getting that wrong produces a faulty disk and a coaster.