There is a certain type of front-end work that's really hard on keyboards, I find. CSS nudging where the thing wants to either stick in place or jump at least 10 pixels, but no amount of tweaking, negative margins or padding will do the trick, all to fit a silly design mandated by a bad freelance client for a project you've already checked out on.

I used to get these odd fist-shaped dents around the JKL area when doing stuff like that. I've mentioned them to the Dell on-site guy when replacing them under warranty, but he didn't have a good explanation either.

They happen a lot less often now that I'm working on my own projects.