I\'ve created a page which combines an inline jQuery UI datepicker . I wan\'t to initiate a callback to the updatepanel when the user clicks a new date to update some data. Now,
I have tried your code for reproducing the error and I can reproduce the error. And I've come to the conclusion that there is some problem with jQuery/UpdatePanels.
If I replace the button with a LinkButton, you can see that the link directly calls __doPostBack(...), the exact same function with the exact same arguments that you are calling. And clicking the link button directly works, but clicking a date doesn't.
So that means that something happens inside jQuery that changes some context. But I have no idea what that would be.