Hi,

When using certain controls, especially those that rely on JavaScript inside an AJAX Update Panel you would often run into problem. This is generally because the control usually initializes itself when the page loads, and when an AJAX update occurs, the HTML contents is changed, so the control do need to be reinitialized, but there is no pageload events, so no initialization actually occurred. Thus causes the problem.

We implemented various improvements on our CallbackPanel control to detect this situation and try to automatically reinitialize the control when possible. However, the control itself, in this case, the DropDownExtender may also try to take care of the situation by itself. DropDwonExtender's implementation is strictly bound to ASP.NET AJAX's UpdatePanel, which means it specifically try to only with ASP.NET AJAX UpdatePanel, which makes it hard for us to intervene. The decision doesn’t seem to be a problem for most users because to be able to use AJAX Extensions, your project must be using ASP.NET AJAX at the first place. We will look into it and see if it is possible to better support these scenarios. In the mean time, you may want to rely on ASP.NET UpdatePanel for that particular scenario.

In many other cases, nothing would work if the control is not prepared to be AJAXed at all. A typical example is that Microsoft's own ASP.NET Menu does not work with its own ASP.NET AJAX UpdatePanel.

Hope this makes sense.

Thanks