SelectedIndex event wont fire in atlas page

I have a drop down and I have added an event which fires when I change the selectedIndex - but this event isnt firing using asp.net 2.0 - this is an atlas project and I cannot get the selectedIndex event to fire - the button event fires fines but not the selectedIndex event.

I used the designer to add the event and have checked all the settings - what can yo do when you cant check the code that fires the event?

I have one button and 1 drp down and the event aint working.

Thanks
Gregor