We had the following situation:
<ext:Panel runat="server" ID="pMenuPl" Layout="FormPanel" AutoDestroy="true" />
<ext:Panel runat="server" ID="pMenuDm" Layout="FormPanel" AutoDestroy="true" />
Added LinkButton's during Page_Load and DirectMethod:
lButton.AddTo(pMenuPl);
this worked in both situations.

In 2.0 and 2.1 this didn't give any exceptions or errors but the linkbuttons just didn't show in both Page_Load and DirectMethod.

To make this work in 2.x:
<ext:Panel runat="server" ID="pMenuPl" IDMode="Static" Layout="VBoxLayout" AutoDestroy="true" />
<ext:Panel runat="server" ID="pMenuDm" IDMode="Static" Layout="VBoxLayout" AutoDestroy="true" />
Page_Load:
pMenuPl.Items.Add(lButton);
DirectMethod
pMenuDm.Items.Add(lButton);
pMenuDm.UpdateContent();
It took me a long time to figure out to use IDMode Static and use UpdateContent.
Then it gave me a error about the FormLayout in combination with the Linkbutton's.
Got it working with VBoxLayout.

Is this by design?
Is there a example where I could have seen how this should have worked now?
Hope other find this helpfull.