How to update/ignore anchor when target is hidden?

[UndercoverDesigns]

I have a UIPanel and a UIButton on my UI.  The UIPanel has it's Bottom Anchor set to the UIButton.  I have the following code:

1. NGUITools.SetActive (NextLevelButton, _LevelComplete);
2. _Player.ToolsPanel.GetComponent<UIPanel> ().ResetAnchors ();
3. _Player.ToolsPanel.GetComponent<UIPanel> ().UpdateAnchors ();

When this executes, the UIButton shows and hides as expected, but the UIPanel doesn't reposition the bottom to fill the space.

Is there a way to force this to occur?  Am I going about this the wrong way?

[ArenMook]

What's a button? Is it just a game object, or does it have a widget on it? The code doesn't actually check for something being disabled. If it's anchored, it will use it. The disabled object may not update its anchors in turn, but its dimensions and position will still be used.