When the buttons are visible on the screen and I click on the button the GroupClick event fires. The same is not true when I click on the overflow button and click an item from the overflow list. Which event should I be checking? Hopefully the images will help explain my issue. When I save off the Explorer Bar settings how do I over write them if a new item is added?
Group Click Event Fires if I click on any of the icons below.
Group Click Does Not Fire if I click on Report Viewer.
It looks like you handled the NavigationContextMenuInitializing event and added menu items for each group. The control doesn't know about these so it can't possibly fire GroupClick. You would need to handle the Click event for those menu items in order to get a notification when they are clicked.