Hmm, so I finally looked at what error comes up sometimes when chat loads... (seems to happen when I reopen Chrome and restore a session, or similar)

Complaining about "Cannot call method 'appendTo' of undefined"

Exception marker seems a bit off if I reformat the code, but I found something that looks a little suspect

V.report_speaking(s.lastOtherRoomMessageTime(), !0);
Ua(a).appendTo(b);

Where Ua does:

var b = $([]) ...;
if (a.events)
    return $.each(...), b;

Guessing it should be more like if (a.events) return $.each(...); else return b;, but not positive.

Oh, no it shouldn't, I had a stupid moment. But presumably it should be returning b unconditionally.