BUT
I can click my online-status bubble, select something and this new control-bar appears (the one with the four icons for the tabs in the big window. actually like this addition

When I toggle the chat now (without closing the window with the [«]-button) the contents of the right window stay in place, only the background gets hidden. (Closing the panel has the intended effect.)
[If I am in-game where the statusbar auto-hides the stuff gets pulled up and disappears, but I figure that's something you know better

To me this looks a bit like there should be nested frames.
As I don't have a working chat-widget now I can't confirm that this only happens when the chat did not connect or if I just haven't seen anyone complain about this bug before