Index: lams_monitoring/src/java/org/lamsfoundation/lams/monitoring/web/MonitoringAction.java
===================================================================
RCS file: /usr/local/cvsroot/lams_monitoring/src/java/org/lamsfoundation/lams/monitoring/web/MonitoringAction.java,v
diff -u -r1.88 -r1.89
--- lams_monitoring/src/java/org/lamsfoundation/lams/monitoring/web/MonitoringAction.java	17 May 2013 09:36:21 -0000	1.88
+++ lams_monitoring/src/java/org/lamsfoundation/lams/monitoring/web/MonitoringAction.java	20 May 2013 09:15:24 -0000	1.89
@@ -1152,11 +1152,11 @@
 	    if (activity.getFloating()) {
 		// these are support activities
 		for (ActivityURL childActivity : activity.getChildActivities()) {
-		    responseJSON.append("support", activityToJSON(childActivity, null, lessonId, learnerId, monitorId));
+		    responseJSON.append("support", activityProgressToJSON(childActivity, null, lessonId, learnerId, monitorId));
 		}
 	    } else {
 		responseJSON.append("activities",
-			activityToJSON(activity, (Long) ret[1], lessonId, learnerId, monitorId));
+			activityProgressToJSON(activity, (Long) ret[1], lessonId, learnerId, monitorId));
 	    }
 	}
 
@@ -1527,7 +1527,7 @@
 	return userJSON;
     }
 
-    private JSONObject activityToJSON(ActivityURL activity, Long currentActivityId, Long lessonId, Integer learnerId,
+    private JSONObject activityProgressToJSON(ActivityURL activity, Long currentActivityId, Long lessonId, Integer learnerId,
 	    Integer monitorId) throws JSONException, IOException {
 	JSONObject activityJSON = new JSONObject();
 	activityJSON.put("id", activity.getActivityId());
@@ -1559,7 +1559,7 @@
 	if (activity.getChildActivities() != null) {
 	    for (ActivityURL childActivity : activity.getChildActivities()) {
 		activityJSON.append("childActivities",
-			activityToJSON(childActivity, currentActivityId, lessonId, learnerId, monitorId));
+			activityProgressToJSON(childActivity, currentActivityId, lessonId, learnerId, monitorId));
 	    }
 	}
 
Index: lams_monitoring/web/monitor.jsp
===================================================================
RCS file: /usr/local/cvsroot/lams_monitoring/web/monitor.jsp,v
diff -u -r1.7 -r1.8
--- lams_monitoring/web/monitor.jsp	17 May 2013 09:36:21 -0000	1.7
+++ lams_monitoring/web/monitor.jsp	20 May 2013 09:15:24 -0000	1.8
@@ -278,7 +278,7 @@
 	</div>
 	
 	<div id="tabSequence">
-		<div class="topButtonsContainer">
+		<div id="sequenceTopButtonsContainer" class="topButtonsContainer">
 			<a target="_blank" class="button" title="<fmt:message key='button.help.tooltip'/>"
 			 href="http://wiki.lamsfoundation.org/display/lamsdocs/monitoringsequence">
 			 <fmt:message key="button.help"/></a>
@@ -294,7 +294,8 @@
 		<div id="completedLearnersContainer" title="<fmt:message key='force.complete.end.lesson.tooltip' />">
 			<img id="completedLearnersDoorIcon" src="<lams:LAMSURL/>images/icons/door_open.png" />
 		</div>
-
+		<img id="sequenceCanvasLoading"
+		     src="<lams:LAMSURL/>images/ajax-loader-big.gif" />
 	</div>
 	
 	<div id="tabLearners">
Index: lams_monitoring/web/css/monitorLesson.css
===================================================================
RCS file: /usr/local/cvsroot/lams_monitoring/web/css/monitorLesson.css,v
diff -u -r1.3 -r1.4
--- lams_monitoring/web/css/monitorLesson.css	17 May 2013 09:36:21 -0000	1.3
+++ lams_monitoring/web/css/monitorLesson.css	20 May 2013 09:15:24 -0000	1.4
@@ -164,6 +164,11 @@
 	overflow: hidden;
 }
 
+img#sequenceCanvasLoading {
+	padding: 5px 0 0 370px;
+	display: none;
+}
+
 div#completedLearnersContainer {
 	padding: 4px 0px 3px 5px;
 	border-top: thin dotted #2E6E9E;
Index: lams_monitoring/web/includes/javascript/monitorLesson.js
===================================================================
RCS file: /usr/local/cvsroot/lams_monitoring/web/includes/javascript/monitorLesson.js,v
diff -u -r1.6 -r1.7
--- lams_monitoring/web/includes/javascript/monitorLesson.js	17 May 2013 09:36:21 -0000	1.6
+++ lams_monitoring/web/includes/javascript/monitorLesson.js	20 May 2013 09:15:24 -0000	1.7
@@ -1,4 +1,5 @@
 // ********** GLOBAL VARIABLES **********
+var refreshInProgress = false;
 // copy of lesson SVG so it does no need to be fetched every time
 var originalSequenceCanvas = null;
 // DIV container for lesson SVG; it gets accessed so many times it's worth to cache it here
@@ -441,6 +442,9 @@
  * Updates learner progress in sequence tab according to respose sent to refreshMonitor()
  */
 function updateSequenceTab(response) {
+	// remove the loading animation
+	$('#sequenceTopButtonsContainer img#sequenceCanvasLoading').remove();
+	
 	var learnerCount = 0;
 	$.each(response.activities, function(){
 		if (this.learners) {
@@ -465,7 +469,7 @@
 		addLearnerIconsHandlers(activity);
 		
 		if (activity.url) {
-			var activityGroup = $('rect[id="act' + activity.id + '"]', sequenceCanvas).parent();
+			var activityGroup = $('g#' + activity.id, sequenceCanvas);
 			activityGroup.css('cursor', 'pointer').dblclick(function(){
 				// double click on activity shape to open Monitoring for this activity
 				openPopUp(LAMS_URL + activity.url, "MonitorActivity", 720, 900, true);
@@ -650,8 +654,6 @@
  */
 function addCompletedLearnerIcons(learners, learnerTotalCount) {
 	var iconsContainer = $('#completedLearnersContainer');
-	// clear all icons except the door
-	iconsContainer.children(':not(img#completedLearnersDoorIcon)').remove();
 	var completedLearnerCount = (learners ? learners.length : 0 );
 	// show (current/total) label
 	$('<span />').attr({
@@ -847,6 +849,11 @@
  * Updates all changeable elements of monitoring screen.
  */
 function refreshMonitor(){
+	if (refreshInProgress) {
+		return;
+	}
+	refreshInProgress = true;
+	
 	if (originalSequenceCanvas) {
 		// put bottom layer, LD SVG
 		sequenceCanvas.html(originalSequenceCanvas);
@@ -888,6 +895,9 @@
 		});
 	}
 	
+	// clear all completed learner icons except the door
+	$('#completedLearnersContainer :not(img#completedLearnersDoorIcon)').remove();
+	
 	// get update data
 	$.ajax({
 		dataType : 'json',
@@ -897,7 +907,18 @@
 			'method'    : 'getLessonProgressJSON',
 			'lessonID'  : lessonId
 		},
+		beforeSend : function(){
+			var sequenceTopButtonsContainer = $('#sequenceTopButtonsContainer');
+			if ($('img#sequenceCanvasLoading', sequenceTopButtonsContainer).length == 0){
+				$('#sequenceCanvasLoading')
+						.clone().appendTo(sequenceTopButtonsContainer)
+						.css('display', 'block');
+			}
+		},
+		
 		success : function(response) {
+			refreshInProgress = false;
+			
 			// update Lesson tab widgets (state, number of learners etc.)
 			updateLessonTab(response);