Sony DVD R/W drive noise



I have a Sony DRU-V200A DVD RW drive and am wondering about a noise I heard when installing it. It sounds as if there is a loose screw or piece of plastic in the drive. I know that this is a normal sound for Lite-on drives as it is the ball bearings in the ABS system shifing. I also saw there is a reference in the Lite-On webpage that discusses this, but my drive is made by Sony. So, is this normal or do I need to go get a exchange from the store? I really hope the DVD’s I have used dont get damaged.