Index: lams_learning/src/java/org/lamsfoundation/lams/learning/service/LearnerService.java
===================================================================
diff -u -r16593058f78a135e25dae055f0fc16c4bed4da42 -r50cbf1b5ae62c1b0e9a6c391e6ecda8ae284ad02
--- lams_learning/src/java/org/lamsfoundation/lams/learning/service/LearnerService.java	(.../LearnerService.java)	(revision 16593058f78a135e25dae055f0fc16c4bed4da42)
+++ lams_learning/src/java/org/lamsfoundation/lams/learning/service/LearnerService.java	(.../LearnerService.java)	(revision 50cbf1b5ae62c1b0e9a6c391e6ecda8ae284ad02)
@@ -61,6 +61,7 @@
 import org.lamsfoundation.lams.learningdesign.GroupingActivity;
 import org.lamsfoundation.lams.learningdesign.LearnerChoiceGrouper;
 import org.lamsfoundation.lams.learningdesign.LearnerChoiceGrouping;
+import org.lamsfoundation.lams.learningdesign.LearningDesign;
 import org.lamsfoundation.lams.learningdesign.OptionsActivity;
 import org.lamsfoundation.lams.learningdesign.SequenceActivity;
 import org.lamsfoundation.lams.learningdesign.ToolActivity;
@@ -354,8 +355,10 @@
     public void createToolSessionsIfNecessary(Activity activity, LearnerProgress learnerProgress) {
 	try {
 	    if ((activity != null) && activity.isToolActivity()) {
-		lamsCoreToolService.createToolSession(learnerProgress.getUser(), (ToolActivity) activity,
-			learnerProgress.getLesson());
+		// make sure that the lesson corresponds to the activity
+		LearningDesign learningDesign = activity.getLearningDesign();
+		Lesson lesson = (Lesson) learningDesign.getLessons().iterator().next();
+		lamsCoreToolService.createToolSession(learnerProgress.getUser(), (ToolActivity) activity, lesson);
 	    }
 	} catch (RequiredGroupMissingException e) {
 	    LearnerService.log.warn("error occurred in 'createToolSessionFor':" + e.getMessage());