New Laptop DVD Drive help!?

My newish (January) HP Pavilion DV3 4100sa laptop's DVD drive has started playing up. When I put a DVD in, it sort of spins it up, but makes loud clicking noises as it spins up and then stops every second or so. It does this for about a minute as it gradually reads the disk's info (much slower than normal, usually it takes only a few seconds for the correct icon to appear in My Computer), and then once it has identified the disk or whatever, it behaves normally and spins steadily at 'max' speed. It behaves completely normally when I put a CD in the drive. What could be the problem?