diff --git a/web/ons-demo/js/debug.js b/web/ons-demo/js/debug.js
index 7b66912..3d3b302 100644
--- a/web/ons-demo/js/debug.js
+++ b/web/ons-demo/js/debug.js
@@ -9,4 +9,23 @@
 		}
 	});
 	return links;
+}
+
+function debug_findswitch(model, dpid) {
+	var sw;
+
+	model.edgeSwitches.forEach(function (s) {
+		if (s.dpid == dpid)
+			sw = s;
+	});
+	model.aggregationSwitches.forEach(function (s) {
+		if (s.dpid == dpid)
+			sw = s;
+	});
+	model.coreSwitches.forEach(function (s) {
+		if (s.dpid == dpid)
+			sw = s;
+	});
+
+	return sw;
 }
\ No newline at end of file
diff --git a/web/ons-demo/js/map.js b/web/ons-demo/js/map.js
index 3849b8d..ad590cb 100644
--- a/web/ons-demo/js/map.js
+++ b/web/ons-demo/js/map.js
@@ -344,7 +344,7 @@
 }
 
 function switchesEnter(switches) {
-	return switchLayer.selectAll('g').data(switches, function (d) {
+	switchLayer.selectAll('g').data(switches, function (d) {
 		return d.dpid;
 	})
 		.enter()
@@ -363,7 +363,9 @@
 
 
 function switchesUpdate(switches) {
-	switches.each(function (d) {
+	switchLayer.selectAll('g').data(switches, function (d) {
+		return d.dpid;
+	}).each(function (d) {
 			// if there's a pending state changed and then the state changes, clear the pending class
 			var circle = d3.select(this);
 			if (d.state === 'ACTIVE' && circle.classed('inactive') ||
@@ -392,7 +394,8 @@
 
 	var switches = coreSwitches.concat(aggregationSwitches).concat(edgeSwitches);
 
-	switchesUpdate(switchesEnter(switches));
+	switchesEnter(switches)
+	switchesUpdate(switches);
 
 	drawLinkLines();