Dvd reads but not Cds

Ok, I am having a problem that i dont understand. My sis has a Dell Inspiron 1300. Recently her combo drive stopped reading cds. When you put a dvd in the drive reads and play it. When you put a cd in it acts as if it will start but never does. Also its a combo burner and it wont burn. Tried to roll back the driver, everything looks fine in device manager, and system restore wasnt helpful. I hope i gave enough info to be of an assistance. oh also tried to reinstall the driver, couldnt find anything useful from dell.