Only send local echo RR if we're at the end

src/components/structures/TimelinePanel.js

@@ -513,12 +513,17 @@ var TimelinePanel = React.createClass({
 
             // do a quick-reset of our unreadNotificationCount to avoid having
             // to wait from the remote echo from the homeserver.
+            // we only do this if we're right at the end, because we're just assuming
+            // that sending an RR for the latest message will set our notif counter
+            // to zero: it may not do this if we send an RR for somewhere before the end.
+            if (this.isAtEndOfLiveTimeline()) {
                 this.props.timelineSet.room.setUnreadNotificationCount('total', 0);
                 this.props.timelineSet.room.setUnreadNotificationCount('highlight', 0);
                 dis.dispatch({
                     action: 'on_room_read',
                 });
             }
+        }
     },
 
     // if the read marker is on the screen, we can now assume we've caught up to the end