Index: lams_central/web/includes/javascript/authoring/authoringProperty.js
===================================================================
diff -u -r82268377d31a6b2c88a736ffdf368156d92af866 -r1b80192b1c9e738b23b09ae2a9577fc10d74f7a4
--- lams_central/web/includes/javascript/authoring/authoringProperty.js	(.../authoringProperty.js)	(revision 82268377d31a6b2c88a736ffdf368156d92af866)
+++ lams_central/web/includes/javascript/authoring/authoringProperty.js	(.../authoringProperty.js)	(revision 1b80192b1c9e738b23b09ae2a9577fc10d74f7a4)
@@ -297,10 +297,10 @@
 			  .on('input', changeFunction);
 			
 			$('.propertiesContentFieldActivityCompletionBased', content)
-				.attr('checked', activity.gateActivityCompletionBased ? 'checked' : null);
+				.prop('checked', activity.gateActivityCompletionBased);
 			
 			$('.propertiesContentFieldStopAtPrecedingActivity', content)
-				.attr('checked', activity.gateStopAtPrecedingActivity ? 'checked' : null);
+				.prop('checked', activity.gateStopAtPrecedingActivity);
 				
 			$('.propertiesContentFieldPassword', content)
 			  .val(activity.password);
@@ -312,7 +312,6 @@
 		
 		if (activity.transitions.to.length == 0){
 			$('.propertiesContentFieldActivityCompletionBased', content)
-				.attr('checked', null)
 				.prop('checked', false)
 				.attr('disabled', 'disabled');
 
@@ -406,9 +405,9 @@
 			$('.propertiesContentFieldTitle', content).val(activity.title);
 			$('.propertiesContentFieldGroupingType', content).val(activity.groupingType);
 			if (activity.groupDivide == 'learners') {
-				$('.propertiesContentFieldLearnerCountEnable', content).attr('checked', 'checked');
+				$('.propertiesContentFieldLearnerCountEnable', content).prop('checked', true);
 			} else {
-				$('.propertiesContentFieldGroupCountEnable', content).attr('checked', 'checked');
+				$('.propertiesContentFieldGroupCountEnable', content).prop('checked', true);
 			}	
 			
 			// create groups/learners spinners
@@ -422,8 +421,8 @@
 			}).attr('value', activity.learnerCount)
 			  .on('input', changeFunction);
 			
-			$('.propertiesContentFieldEqualSizes', content).attr('checked', activity.equalSizes ? 'checked' : null);
-			$('.propertiesContentFieldViewLearners', content).attr('checked', activity.viewLearners ? 'checked' : null);
+			$('.propertiesContentFieldEqualSizes', content).prop('checked', activity.equalSizes);
+			$('.propertiesContentFieldViewLearners', content).prop('checked', activity.viewLearners);
 			$('.propertiesContentFieldNameGroups', content).click(function(){
 				PropertyLib.openGroupNamingDialog(activity);
 			});
@@ -832,8 +831,7 @@
 			});
 		}
 
-		$('.propertiesContentFieldDefault', content).attr('checked',
-				transition.branch && transition.branch.defaultBranch ? 'checked' : null);
+		$('.propertiesContentFieldDefault', content).prop('checked', transition.branch && transition.branch.defaultBranch);
 	}
 },
 
@@ -1109,7 +1107,7 @@
 					var dialog = layout.outputConditionsDialog,
 						activity = dialog.data('parentObject'),
 						outputSelect = $('#outputSelect', dialog),
-						emptyOption = $('option[value="none"]', outputSelect).attr('selected', 'selected'),
+						emptyOption = $('option[value="none"]', outputSelect).prop('selected', true),
 						// conditions can have names like "output.name#6", but real output names do not have a suffix
 						outputName = activity.conditionsToBranches && activity.conditionsToBranches.length > 0
 								 	 ? activity.conditionsToBranches[0].condition.name.split('#')[0] : null;
@@ -1143,8 +1141,8 @@
 										   .appendTo(outputSelect);
 							// select the output for which mappings were already defined
 							if (this.name == outputName) {
-								option.attr('selected', 'selected');
-								emptyOption.attr('selected', null);
+								option.prop('selected', true);
+								emptyOption.prop('selected', false);
 							}
 						});
 					}
@@ -1508,7 +1506,7 @@
 	 */
 	fillGroupingDropdown : function(activity, grouping) {
 		// find all groupings on canvas and fill dropdown menu with their titles
-		var emptyOption = $('<option />').attr('selected', 'selected'),
+		var emptyOption = $('<option />').prop('selected', true),
 			groupingDropdown = $('.propertiesContentFieldGrouping', activity.propertiesContent).empty().append(emptyOption),
 			groupings = [];
 		
@@ -1527,8 +1525,8 @@
 						// store reference to grouping object
 						.data('grouping', this);
 			if (this == grouping) {
-				emptyOption.removeAttr('selected');
-				option.attr('selected', 'selected');
+				emptyOption.prop('selected', false);
+				option.prop('selected', true);
 			}
 		});
 	},
@@ -1589,8 +1587,8 @@
 						// store reference to grouping object
 						.data('input', this);
 			if (this == input) {
-				emptyOption.removeAttr('selected');
-				option.attr('selected', 'selected');
+				emptyOption.prop('selected', false);
+				option.prop('selected', true);
 			}
 		});
 	},
@@ -1630,8 +1628,8 @@
 			
 			// select the default output
 			if (activity.gradebookToolOutputDefinitionName == this.name) {
-				option.attr('selected', 'selected');
-				emptyOption.attr('selected', null);
+				option.prop('selected', true);
+				emptyOption.prop('selected', false);
 			}
 		});