Go forward in time to June 2013.
Some time before or during the GTK+ hackfest, Emacs on my laptop started acting strange. C-SPC wasn't working (a major catastrophe), and when using a Latin American keymap, it was spewing nonsense like <dead-acute> is undefined.
Today I finally figured it out, but just by comparing things between my machine-where-emacs-works and my laptop. It turns out that ibus had gotten installed on my laptop, and it was screwing things up.
TL;DR Emacs stopped handling C-SPC and dead keys; I uninstalled the ibus package and everything works again.
I have no idea of how Emacs users manage to live when they actually need to use ibus for input methods.
Go backward in time to April 2013.Federico Mena-Quintero <email@example.com> Wed 2013/May/08 20:06:20 CDT