Are you using Nero ?
When you first start Nero Express you'll see 'Which recorder would you like to use'
Here there will be a choice, one for the CD-R(W) part of the drive and the other the DVD-R(W).
Select the DVD part and you'll be happily burning DVD's
Nero keeps the two seperated as not to burn DVD to CD etc.
Latest fimware is A105, just in case you need it.
Hope this helps.