I am having the below problem in IE (Firefox its working fine)
I have a search screen with date field for which I used rich:calendar component. On IE when the popup is opened, the buttons, comboboxes and other date fields are overimposed on this popup. I mean they are also visible and hindering popup view.
I had similar problem with modalPanel and used attribute tridentIVEngineSelectBehavior="hide". This fixed the issue with modal panel. I couldn't find similar fix with Calendar component.