C#: How to avoid TreeNode check from happening on a double click event

So I have a TreeView in a C# windows form app. What I need is for some nodes to be "locked" so that they cannot be checked (or unchecked), based on a parameter.

What I am doing now is this:

private void tv_local_BeforeCheck(object sender, TreeViewCancelEventArgs e) {
    TNode node = (TNode)e.Node;
    //if a part node, cancel the action.
    if (node.Type == "Part") {
        e.Cancel = true;     
    }
    //if a locked node, cancel the action
    if (node.Locked == true) {
        e.Cancel = true;
    }
}

This code works great on a single click of the checkbox, but if the user double clicks on a checkbox, it still checks/unchecks.

I have tried playing with the nodeMouseDoubleClick event, but that doesnt really help, since I cannot cancel the event...

Is there any ideas out there how to cancel a double click event on a node?... or anything else? Thanks