Asynchronous web service: Error in server

[ori]

Hi !

We have a problem in a web application with an asynchronous webservice
that we have developed. There is an asp.net page that invokes a remote
web service (in the same application) asynchronously. At our
development computers, this invocation completes with no problem and
the web service is correctly executed. However, after deploying the
application in the production server, this invocation is not working
properly. I can't find exactly why but, by tracing the page, it seems
that the method EndXXX in the callback function doesn't work.

Any help on why can we be experiencing this behaviour and how to solve
it will be appreciated. I include the code we are using for the
invocation:

Private Sub WebServiceCall()

Dim service As localhost.Service = New localhost.Service
Dim callback As AsyncCallback = New AsyncCallback(AddressOf
WebServiceCallBack)

Dim state As New State(service)

Trace.Write("WebServiceCall()")

service.BeginMethod(callback, state)

End Sub

Private Sub WebServiceCallBack(ByVal result As IAsyncResult)

Dim state As Asynchronous.State = CType(result.AsyncState,
State)
Dim service As localhost.Service = CType(state.WebService,
localhost.Service)

Trace.Write("WebServiceCallBack().Begin()") - This TRACE Is
Executed

Dim res As String = CType(service.EndMethod(result), String)

Trace.Write("WebServiceCallBack().End() :: result: " & res & "
session: " & state.SessionId)
- This TRACE Is NOT Executed

End Sub


Thx in advance,
ori