Many trusted websites offer a live chat support (for example www.libertyreserve.com). The chat is always opened in a new Iceweasel window without the Onion logo in it. Does this mean that the original IP is leaked when using the chat window or even opening it?

The chat in question is probably opened as a pop-up, which and such windows do not include addon controls like the Torbutton's onion icon. Even when that happens Torbutton's security features are still in effect, so it's safe.
Comment by Tails Mon 23 Apr 2012 12:37:47 PM CEST