First Button Click posts back but event not triggered. On Second click the event is triggered

ASP .NET 1.1 VS 2003

The web form has copule of dropdown, calendar control and 2 buttons.

One of the button has a problem. On first click, page is loaded but button event is not triggered. On second click the page load is called and the button event is triggered.

What is going on?

 

AR
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