Question on Fragged HDD's and Data back-up burning

Ok I don't know if this is the right place to put this thread so if its not please move it to the appropriate place, thanks

I am using the latest Nero...for the burning program

Well I am backing up a korean drama I dled and the first disc went though clean, then for the second disc I ended up getting verification errors, so I decided to try again, but it happened again, with more errors I might add. I decided not to waste anymore DVD-R's and went hunting for a solution which eluded me. I decided to just defrag the drive that had the files (which according to the drive map was pretty separated but NOT fragmented) Then I tried to back it up again and it worked perfectly.

My question is would a fragged up drive make the burning process harder? Or did I just run into 2 bad DVD-R's in a row???

I use memorex DVD-R's by the way.

Jam it back in, in the dark.