I'm posting this under 8x and here in generic windows mobile, just in case it happens to Lumia customers too--
Even if I silence my 8x (ringer and vibrate) I get three tones from the phone if I miss a call. This does not seem to happen on my co-worker's 8x from T-Mobile, so does anyone know what the deal is with this? It sounds like the old school noise you would get when your call was dropped. And, it's horrible because I can't silence it no matter what (unless I turn off the phone).