I've had my pc for about 2 yrs now and i've only noticed recently that my supposed dvd drive wont play dvds

(it also wouldn't play a couple of cds, but they would work in my cd-rw so i didnt mind)
When i put a dvd into the drive the thing lights up like its processing or sumthing and i hear the disk spin a bit, but then nothing. I can't even go through "my computer" to get to it. I've now noticed that windows lists it as a cd-drive under type, although its name is dvd drive (d

.
Any ideas on whats going wrong?
Btw im running windows xp sp2 and the dvd drive is a samsung sd-616t that came w/ the pc. Thanks for any help you can give me
