By default, the Fn key on an external keyboard brings up a popup menu in several applications (xterm, Notes and evince, for example). In some apps, this prevents me from using the Fn + numeric key combination. Some months ago, I changed a setting somewhere to disable the Fn key from bringing up the popups. Now, I've installed the new OS update and, of course, it's reverted to the default behaviour.

The problem is, I can't remember what setting I changed before. I've searched the forum for "Fn menu key" but found nothing relevant (even though I'm pretty sure it was on this forum that I found the answer in the first place.

Can anybody help? Thanks.