report viewer keep showing report is being generated

hi all,

i developed a web app with embedded report viewer to show the reports (server report). everything works alright. i created a setup file to install it at another machine. everything looks ok except that when i want to view the report, it will always show 'Report is being generated' for a very long time when it only takes a few seconds when i view it on report server.

i found the following warning in event viewer (application):

Process information:

Process ID: 4976

Process name: aspnet_wp.exe

Account name: DWPC1\ASPNET

Exception information:

Exception type: SoapException

Exception message: System.Web.Services.Protocols.SoapException: Execution 'icwhpl55jbfwm355yxxw152i' cannot be found > Microsoft.ReportingServices.Diagnostics.Utilities.ExecutionNotFoundException: Execution 'icwhpl55jbfwm355yxxw152i' cannot be found

at Microsoft.ReportingServices.WebServer.SessionStarterAction.CreateExisting()

at Microsoft.ReportingServices.WebServer.ReportExecutionService.GetExecutionInfo(ExecutionInfo& executionInfo)

End of inner exception stack trace

at Microsoft.ReportingServices.WebServer.ReportExecutionService.GetExecutionInfo(ExecutionInfo& executionInfo)

Request information:

Request URL: http://localhost/AirForce/Reserved.ReportViewerWebControl.axd?ReportSession=icwhpl55jbfwm355yxxw152i&ControlID=56545a8d-aaa2-4050-b66e-3a18d3c931d8&Culture=1033&UICulture=1033&ReportStack=1&OpType=SessionKeepAlive&Interval=539000

Request path: /AirForce/Reserved.ReportViewerWebControl.axd

User host address: 127.0.0.1

User: DWPC1\dwdvpr

Is authenticated: True

Authentication Type: Negotiate

Thread account name: DWPC1\ASPNET

Thread information:

Thread ID: 7

Thread account name: DWPC1\ASPNET

Is impersonating: False

Stack trace: at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)

at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)

at Microsoft.SqlServer.ReportingServices2005.Execution.ReportExecutionService.GetExecutionInfo()

at Microsoft.SqlServer.ReportingServices2005.Execution.RSExecutionConnection.GetExecutionInfo()

at Microsoft.Reporting.WebForms.ServerReport.TouchSession()

at Microsoft.Reporting.WebForms.SessionKeepAliveOperation.PerformOperation(NameValueCollection urlQuery, HttpResponse response)

at Microsoft.Reporting.WebForms.HttpHandler.ProcessRequest(HttpContext context)

at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Please help. No specific error message to help me debug. i have no idea what's wrong.

Thanks!

I saw this message quite often before I've tried this approach: before trying to change the report path or HistoryId do the following:
ReportViewer1.ServerReport.ReportPath = "";
ReportViewer1.ServerReport.Refresh();

However, I still get sometimes the message "ASP.NET session expired" or something similar.