Now that my one year warranty is about to expire I'm perhaps getting more sensitive to everything on my Macbook. Here is what I'm seeing this afternoon looking at the Macbook. If you took the screen and divided it vertically down the middle, then put a border around each two "boxes" of about an inch, with the border being considerably darker than the inside of the box, this is what I'm seeing. You don't notice it much in normal use, but if you're booting up, have a solid background, its quite noticeable. Worth taking in? Should ask another perhaps related question. When you connect the Macbook to an external monitor, do you hotplug it or turn the machine off first? If you read the manual, it sounds like you hotplug it.