This can happen if there is a disc inside the drive and if the disc is spinning you hear a "scratching" noise when you hold the laptop like that.
You can't see it because it barely bends but bends enough to damage make the disc touche the drive, I've heard that noise some times but didn't damage the drive but a friend of mine wasn't so lucky and had to replace the drive, it just stop reading discs.
Does anyone else have the same opinion or had this problem?