Comment 1 for bug 1494606

Whenever I see layouts and weird input, I immediately think about IBus.

Are you running IBus?
If yes, what happens if you kill the process? (You may have to use system settings to switch between keyboard layouts after killing it.)

We did make some modifications that were to disable IBus messing up the composed characters (ö, ê, etc) not being broadcast to receivers, and this was down to IBus not passing on some events.

You could try reverting the change in http://bazaar.launchpad.net/~gnome-terminator/terminator/trunk/revision/1611
and see if it start behaving correctly afterwards.

All this will help narrow down the cause. (I'm native English, so IBus, and multi-layouts and the like are a little mysterious, so this is more about me helping you to find the source of the problem :-) )