Noted at http://www.quora.com/How-can-I-find-out-from-where-I-am-being-signed-into-Google-Talk-from-other-clients-or-devices "Google updated Talk to Hangout. So if u r signed in into Google Hangout, you r visible on Talk too. It shud nt happen if you r signed off Google Hangout."
If I was to tackle this I'd try the old change the password trick. That way the other devices can't auto login. Sorry to say but Google moved the cheese.
Bob
I have got the problem in my Google Talk: "Oops! You are not invisible because you're logged into Google Talk from another client, device, or location that doesn't support invisibility". I tried to fix the problem using site https://karthikkn.wordpress.com/2013/07/16/fixed-the-always-online-problem-with-google-chat/ but I could not manage a protocol. When I had confirmed Google talk protocol in Pidgin Add Account table then I automatically got XMPP protocol and I am not able to change it. How to solve this problem ?

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