Looks like the form decorator has compatibiliy issues with microsoft's ajaxToolkit ConfirmButtonExtender and ModalPopupextender. For every instance of the extender a bracket "]" appears. If I select "buttons" for ControlsToSkip the issue goes away but now my buttons don't match the rest of my site. This is probably because the popup extender has buttons embedded in it. I see Zone as a ControlsToSkip option. What is a Zone and can I enclose the extender in such a Zone?