diff --git a/src/controllers/molecules/MessageComposer.js b/src/controllers/molecules/MessageComposer.js
index 74e47fcd..3bd0f7f8 100644
--- a/src/controllers/molecules/MessageComposer.js
+++ b/src/controllers/molecules/MessageComposer.js
@@ -182,12 +182,12 @@ module.exports = {
 
         var self = this;
         setTimeout(function() {
-            if (self.refs.textarea.getDOMNode().value != '') {
+            if (self.refs.textarea && self.refs.textarea.getDOMNode().value != '') {
                 self.onTypingActivity();
             } else {
                 self.onFinishedTyping();
             }
-        }, 10);
+        }, 10); // XXX: what is this 10ms setTimeout doing?  Looks hacky :(
     },
 
     onEnter: function(ev) {
diff --git a/src/controllers/pages/MatrixChat.js b/src/controllers/pages/MatrixChat.js
index 71c9140c..7c32a66d 100644
--- a/src/controllers/pages/MatrixChat.js
+++ b/src/controllers/pages/MatrixChat.js
@@ -166,7 +166,8 @@ module.exports = {
                         break;
                     }
                 }
-                roomIndex = Math.max((roomIndex + roomIndexDelta) % allRooms.length, 0);
+                roomIndex = (roomIndex + roomIndexDelta) % allRooms.length;
+                if (roomIndex < 0) roomIndex = allRooms.length - 1;
                 this.focusComposer = true;
                 this.setState({
                     currentRoom: allRooms[roomIndex].roomId
@@ -250,10 +251,12 @@ module.exports = {
                 case 38:
                     dis.dispatch({action: 'view_prev_room'});
                     ev.stopPropagation();
+                    ev.preventDefault();
                     break;
                 case 40:
                     dis.dispatch({action: 'view_next_room'});
                     ev.stopPropagation();
+                    ev.preventDefault();
                     break;
             }
         }