I am having issues with a collapsible panel I'm using which contains the RadDatePicker. It works fine in IE7 forward but in compatibility mode or IE6 the date input and calendar button do not reside inside of the collapsible panel. I have tried changing the ZIndex property on the RadDatePicker with the same results. I can add a z-index style setting to the date input or calendar element and it will place the particular element behind the panel but not inside. Any ideas on how to fix this?