Index: lams_common/src/java/org/lamsfoundation/lams/tool/service/LamsToolService.java
===================================================================
diff -u -r2485ce33e55a921bdcde94e4f242da5da3cf1fc4 -rf08b5947762a528d2790edb34173a2bbcb5fa2e0
--- lams_common/src/java/org/lamsfoundation/lams/tool/service/LamsToolService.java	(.../LamsToolService.java)	(revision 2485ce33e55a921bdcde94e4f242da5da3cf1fc4)
+++ lams_common/src/java/org/lamsfoundation/lams/tool/service/LamsToolService.java	(.../LamsToolService.java)	(revision f08b5947762a528d2790edb34173a2bbcb5fa2e0)
@@ -160,13 +160,18 @@
 
     @Override
     public void setActivityEvaluation(Long toolContentId, String toolOutputDefinition) {
+	ToolActivity toolActivity = activityDAO.getToolActivityByToolContentId(toolContentId);
+	ActivityEvaluation evaluation = toolActivity.getEvaluation();
+
 	if (StringUtils.isEmpty(toolOutputDefinition)) {
+	    if (evaluation != null) {
+		toolActivity.setEvaluation(null);
+		activityDAO.delete(evaluation);
+	    }
 	    gradebookService.removeActivityMark(toolContentId);
 	    return;
 	}
 
-	ToolActivity toolActivity = activityDAO.getToolActivityByToolContentId(toolContentId);
-	ActivityEvaluation evaluation = toolActivity.getEvaluation();
 	boolean isToolOutputDefinitionChanged = true;
 	if (evaluation == null) {
 	    evaluation = new ActivityEvaluation();