diff --git a/trunk/ProcessHacker/Components/ProcessTree/ProcessTreeModel.cs b/trunk/ProcessHacker/Components/ProcessTree/ProcessTreeModel.cs
index 9fae0e82c..729843bd0 100644
--- a/trunk/ProcessHacker/Components/ProcessTree/ProcessTreeModel.cs
+++ b/trunk/ProcessHacker/Components/ProcessTree/ProcessTreeModel.cs
@@ -49,49 +49,52 @@ namespace ProcessHacker
         public void Add(ProcessItem item)
         {
             ProcessNode itemNode = new ProcessNode(item);
-
-            // Add the process to the list of all processes.
-            _processes.Add(item.Pid, itemNode);
-
-            // Find the process' parent and add the process to it if we found it.
-            if (item.HasParent && _processes.ContainsKey(item.ParentPid))
+           
+            if (!_processes.ContainsKey(item.Pid))
             {
-                ProcessNode parent = _processes[item.ParentPid];
+                // Add the process to the list of all processes.
+                _processes.Add(item.Pid, itemNode);
 
-                parent.Children.Add(itemNode);
-                itemNode.Parent = parent;
-            }
-            else
-            {
-                // The process doesn't have a parent, so add it to the root nodes.
-                _roots.Add(itemNode);
-            }
-
-            itemNode.RefreshTreePath();
-
-            // Find this process' children and fix them up.
-
-            // We need to create a copy of the array because we may need 
-            // to modify the roots list.
-            ProcessNode[] roots = _roots.ToArray();
-
-            foreach (ProcessNode node in roots)
-            {
-                // Notice that we don't replace a node's parent if it 
-                // already has one. This is to break potential cyclic 
-                // references.
-                if (node.Parent == null && node.ProcessItem.HasParent && node.PPid == item.Pid)
+                // Find the process' parent and add the process to it if we found it.
+                if (item.HasParent && _processes.ContainsKey(item.ParentPid))
                 {
-                    // Remove the node from the root list and add it to our 
-                    // process' child list.
-                    _roots.Remove(node);
-                    itemNode.Children.Add(node);
-                    node.Parent = itemNode;
-                    node.RefreshTreePathRecursive();
-                }
-            }
+                    ProcessNode parent = _processes[item.ParentPid];
 
-            this.StructureChanged(this, new TreePathEventArgs(new TreePath()));
+                    parent.Children.Add(itemNode);
+                    itemNode.Parent = parent;
+                }
+                else
+                {
+                    // The process doesn't have a parent, so add it to the root nodes.
+                    _roots.Add(itemNode);
+                }
+
+                itemNode.RefreshTreePath();
+
+                // Find this process' children and fix them up.
+
+                // We need to create a copy of the array because we may need 
+                // to modify the roots list.
+                ProcessNode[] roots = _roots.ToArray();
+
+                foreach (ProcessNode node in roots)
+                {
+                    // Notice that we don't replace a node's parent if it 
+                    // already has one. This is to break potential cyclic 
+                    // references.
+                    if (node.Parent == null && node.ProcessItem.HasParent && node.PPid == item.Pid)
+                    {
+                        // Remove the node from the root list and add it to our 
+                        // process' child list.
+                        _roots.Remove(node);
+                        itemNode.Children.Add(node);
+                        node.Parent = itemNode;
+                        node.RefreshTreePathRecursive();
+                    }
+                }
+
+                this.StructureChanged(this, new TreePathEventArgs(new TreePath()));
+            }
         }
 
         public void Modify(ProcessItem oldItem, ProcessItem newItem)