If you have a daypilot control in an update panel, ajax history is enabled and you add an ajax history point on page load, daypilot controls will not work in Internet Explorer (tested with IE 8). DayPilot events have to be in CallBack. It is working in PostBack, but it's slow. The synchronization between a DayPilotNavigator and a calendar is not working either if ajax history is involved on page load.
We add history points on page load to make sure certain elements are included in the link, for example the page # of a list etc. This way, a user can copy paste a link and have the exact same page.
If we put ScriptManager.GetCurrent(Page).EnableHistory = false in our page, then daypilot is working as normal, but it disable a lot of features in our page.
As soon as we use something like this ScriptManager.GetCurrent(Page).AddHistoryPoint("h", id); in our page load with a daypilot in IE8, CallBack events are not working anymore.