Hi Maxim, You remember a bug that we just found couple of weeks now and you fix in the 4.0.3 release. It was about when you quit a room, look like the microphone was not closed correctly and people inside the room continue to hear you. Like i said, it's fix in 4.0.3 release.
Now, i think we found another bug (with Internet Explorer, Chrom, it's OK). It's like the same bug, but inverse :( If someone was in a room to take place in a conference and he decide to quit and stay in the lobby room, it continue to hear the person that is still talking in the room that i was in couple of second ago. I hope i'm enough clear to help you test and fix that bug. Thank's Martin C.
