Steps to Reproduce

 run code

http://zkfiddle.org/sample/2q88k7k/3-groupbox-rod-visible

Current Result

open JS console, run code:

 zk.$('$bt2') > returns widget (widget exists)

zk.$('$bt2').desktop > return null (widget has not received a desktop)

Expected Result

 Widgets should receive a desktop when initialized by groupbox ROD

Debug Information

 There is a 

if (!w._visible && zkmax.rod(w))

line in groupbox-rod.js (in zkcml) which prevents zkmax.rod(w) to trigger on visible=false widgets.

This also prevent these components to receive a desktop during bind_ since it is not fired.

Workaround

disable groupbox ROD 

<custom-attributes org.zkoss.zul.client.rod="false"/>

https://www.zkoss.org/wiki/ZK_Developer's_Reference/Performance_Tips/Client_Render_on_Demand#Enable_or_Disable_Client_ROD