On my macbook, I noticed that there is definite gap between the lid and the body of the notebook when closed. This is much more pronounced on the left side than on the right. I've tried to determine whether it's the body or the lid, but arrived at the conclusion that it's both - the body is bent downward and the lid upward. How can I get Apple to fix this? It seems to be a common problem and they are rather reluctant to fix it.