I've had my (SR) macbook since pretty much release date but I hadn't noticed this before. Was wondering if other people's MB are like this. As you are facing the machine it is on the right hand side, both top and bottom, but also in the top row in the second set of holes from the right the 4 slot is blocked. This may be the cause of the slight grey area I am seeing on the left side of my screen near the vent due to increased air flow/heat. Hopefully you can see what I mean.