Trigger event for nested Updatepanel not working

I have the following situation:

Updatepanel
   dynamically loaded Usercontrol
      Button
      UpdatePanel2

I am loading a Usercontrol with another Updatepanel inside of it. Now in this usercontrol, i have a button which is registered as an async postback trigger for the 2nd Updatepanel. However when I click the button, nothing happens. While debugging, it does not even step into the Click event of the Button which sits in the usercontrol of course. The Parent Updatepanel ist set to Updatemode conditional and ChildrenAsTriggers="false". The nested UpdatePanel2 is set to Updatemode=Conditional. I just want th开发者_开发技巧e Parent Updatepanel to do nothing and the button to fire its event so that I can load some data in the nested updatepanel. Can anyone offer some insight? I am using ASP.NET 3.5.