here is what i do :
- create a "border" layout panel
- create a west panel with "form" as layout property (called "westpanel")
- add a combo box to the form "westpanel", set a store, some properties of the cbo..
- i do a "duplicate" context menu command on the combo.
i expect to see the 2 combo box with the second one under the first one.
so the IDE and the preview show the 2 combo box on the same position : unable to set the second under the first combo !
so to understand why, i edit the ext designer projet code to see that the IDE has set a jsFile property to my 2 combos but
i never ask to promote the combo as class.
when i delete the 2 combo, and recreate 2 combo manually i got not problem : the second combo is under the first.