Null parent node on custom tree node after populate on demand

[John Bankhead]

I have inherited from treeview to create an object that overrides CreateNode.
This custom treeview supports a custom tree node with four additional
attributes, a postrender override as well as a load and save view state.

The problem arose in the bottom level of the Treeview which is populated on
demand. While the custom values are in the node, the parent attribute is
equal to null. The node does indeed have a parent. Any ideas why this might
happen?

protected void tree2_TreeNodePopulate(object sender, TreeNodeEventArgs e)
{
DataAccessProvider dap = new DataAccessProvider(null);
FaultTreeNode node = (FaultTreeNode)(e.Node);
AddFMILevel(ref node, Convert.ToInt64(node.ItemID), NodeType.FMI, dap);
}