I have a Sony DVD-RW DRU-710A that will not burn files onto any format of DVD (-R,+R,-RW,+RW), but only onto CDs. I have been using Nero 6 successfully with CDs. But when I try DVDs, at the start of the burning prompt, the program informs me that it cannot proceed because I have to use a CD, not a DVD. How can I solve this?