I'm having a bit of a frustrating occurrence at the moment. I use Opera 20 on Mavericks but retained my old Opera 12 install in my applications folder. Certain apps and links have a tendency to open Opera 12 instead of or as well as Opera 20. Of particular frustration is 1Password, which has a handy quick login functionality but which simultaneously opens both versions. How can I dissociate Opera 12 from my workflow? I have data in notes and things which I'd still like to have access to. I've renamed it, moved its location - no dice.

Any tips?