Cds not finalised

Hello,
I have a laptop,using the latest Itunes version to burn CD's and put them onto the ipod. I have not changed anything in the settings whatsowever however when I want to burn a cd ( from a created playlist ) in itunes ,it starts burning alright,however does not finalise the cd. I tried various brands,tried to clean the laser,same issue.
Second problem,when I put a cd into the drive it is recognised,but when I listen back to it on ipod it stuttes.
Im not sure whether this is a hardware or software problem. The drive looks a bit scratched ( the plastic where you put the cd on ). i tried to burn with a diiferent programme ,not itunes,same problem.
do I need to buy a new cd/dvd writer ?
I could always burn and read cds normally,suddenly it stopped functioning.

thanks for some tipps,

Frauke