Index: lams_gradebook/src/java/org/lamsfoundation/lams/gradebook/web/action/GradebookAction.java
===================================================================
diff -u -r351695e545e0997681c3d5a5f1b60e18acff7e04 -rb7097f75fa02948b4092c56103ea3eb853297016
--- lams_gradebook/src/java/org/lamsfoundation/lams/gradebook/web/action/GradebookAction.java	(.../GradebookAction.java)	(revision 351695e545e0997681c3d5a5f1b60e18acff7e04)
+++ lams_gradebook/src/java/org/lamsfoundation/lams/gradebook/web/action/GradebookAction.java	(.../GradebookAction.java)	(revision b7097f75fa02948b4092c56103ea3eb853297016)
@@ -386,7 +386,18 @@
     	    HttpServletResponse response) throws Exception {
 	initServices();
 
-    	Long activityID = WebUtil.readLongParam(request, AttributeNames.PARAM_ACTIVITY_ID);
+	String rowID = WebUtil.readStrParam(request, AttributeNames.PARAM_ACTIVITY_ID);
+	
+	Long activityID = null;
+	
+	// Splitting the rowID param to get the activity/group id pair
+	String[] split = rowID.split("_");
+	if (split.length == 2) {
+	    activityID = Long.parseLong(split[0]);
+	} else {
+	    activityID = Long.parseLong(rowID);
+	}
+	
     	Activity activity = gradebookService.getActivityById(activityID);
     	
     	if (activity != null) {