So, there I was, using my Macbook. I noticed it was rocking about a bit, like there was a small coin or something underneath it -- nothing unusual, as my desk is often messy and stuff creeps under things all the time. I fish around under there, but there's nothing there. I carry on, but it still rocks around on something. I switch the Macbook off, and flip it over, only to find that the edge of the battery is sticking up a bit.
I did a bit of googling, and discovered that this is not only "normal", but it's something so normal Apple refuses to acknowledge or compensate its existence. Macbook batteries just do this. Every so often they just shrug and go "Y'know what, screw this cruel world. I'm going to expand like a piece of popcorn and I might just take this laptop with me."
As the cell in the battery expands, it pushes on the nearby components of the computer. In the case of my particular model of Macbook, the first victims are the Airport cart and RAM, followed by everything else.
I popped the battery out and shoved it in a drawer, ordering another one from Apple's online store, as there was clearly no way of claiming the thing under any kind of warranty or insurance.
New battery arrived. All good. More to come. Stay tuned.