Dvd gives out after 1 hour of movies

Hello,
I have an HP Pavilion dv2000 running vista and recently have had problems with the last few movies I've played on my laptop. After about an hour of the movie playing, the dvd drive makes noises like its trying to read the dvd, but the quickplay center always then shows that its no longer responding. i've tried using different media players, but movies always get stuck at the same 1 hour point