Joap,
I hope this help.
The DVD that you've bought is not supported by your DVD drive.
You've mentioned that your DVD drive support DVD+R and DVD+RW,
but the DVD that you've got is DVD-R.
Double check this info.
I had the same problem before with my Acer. So I bought only DVD RW (my machine support both DVD+RW, and DVD-RW, your should too.)