AutoCompleteExtender in ascx doesn't works..

I've this set:

AutoCompleteExtender (4.1.4.0) in update panel in user control (ascx) and webservice under his ascx.vb and doesn't works.

So I've tested the same markup and webservice method in a simple aspx page and works, so I've some doubt:

- AutoCompleteExtender works in ascx file with webservice function under his code?

- AutoCompleteExtender works in an update panel?

I've always problem to create webservice method using wizard on the control, it return always: Cannot create page method GetCompletionList because no CodeBehind or CodeFile was found! - but I've CodeBehind file..sure!

Thanks!

Gio