Macbook 4,1 internal keyboard seemingly mismapped after login

[statokinetics]

Hello. I am using a Macbook 4,1 with 9.10, and I've noticed a strange recurring behavior for a while with the internal keyboard after a fresh boot. They keyboard types fine at the login screen, but after being logged in for the first time, some keys produce keystrokes (which do not match up with the US English Macbook keyboard mapping) while some don't produce anything. After navigating via trackpad to start a guest session, the keyboard works fine within the guest session, and continue to work fine after logging back out to the original session. Not a difficult workaround, but I wonder, why does it happen?

[tom4everitt]

Interesting. What happens if you create a new normal user, and log in as that user the first thing you do? It might just be some old config files in your home folder that are making a mess.