New 15" macbook pro snapping sound left side

Brand new, quad core i7. When I let it sit for a while with the lid closed. When I open it, I hear a snap on the left side back by where the LCD and chassis come together. Like plastic snapping. If I open it and close it again right away to try to find the source of the sound. It goes away. Close the lid for about an hour and it does it again. Not sure if its a hinge issue or something not put together quite right. I cant figure it out. Just wondering if anyone else is experiencing the same issue.