OneWay and Impersonate problem

[Davide Bedin]

Working on VS 2005 Beta 2

In my web service I impersonate a specific user with limited rights using
the <identity impersonate="true" userName="someone" password="something"/>
in the web.config.
Everything works as expected. The web service has access to the SQL db using
integrated security.

If I enable the OneWay property of SoapDocumentMethod attribute for a web
method the web service is no longer impersonating the user so any attempt to
access secured resources fails.

Is this beaviour by design? How can I use OneWay property without having to
change my choices on security?

Thanks in advance,
Davide Bedin