I have recently inherited a MacBook Pro from a colleague who has left the company. One of the annoying features that they had set up is that in every window/application that I can type the system will automatically try to enter closing quotes when ever I enter a single one.
I think the main problem is I don't know how it is supposed to work, as sometimes it adds it in, other times it does not. Either way, I hate it.
The way it appears is, as soon as you type the single character
~ (and probably multiple others) an underscore appears underneath it and I have to hit the space bar to accept the single version (did I mention it was annoying).
I've looked in the preferences and I can't see anything that could be causing this.