Fixed another bug causing items to get orphaned sometimes (See #197)

HISTORY.md

@@ -3,7 +3,9 @@ http://visjs.org
 
 ## not yet released, version 3.1.1
 
-(no changes yet)
+### Timeline
+
+- Fixed items in groups sometimes being displayed but not positioned correctly.
 
 
 ## 2014-07-22, version 3.1.0

lib/timeline/component/Group.js

@@ -258,7 +258,7 @@ Group.prototype.add = function(item) {
   this.items[item.id] = item;
   item.setParent(this);
 
-  if (item instanceof ItemRange && this.visibleItems.indexOf(item) == -1) {
+  if (this.visibleItems.indexOf(item) == -1) {
     var range = this.itemSet.body.range; // TODO: not nice accessing the range like this
     this._checkIfVisible(item, this.visibleItems, range);
   }