Ecco la soluzione sotto .NET

codice:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim rpt As PROVA3 = New PROVA3()
        Dim mStream As New System.IO.MemoryStream()
        rpt.Run(False)

        Dim xPDF As DataDynamics.ActiveReports.Export.Pdf.PdfExport = New DataDynamics.ActiveReports.Export.Pdf.PdfExport()
        xPDF.Export(rpt.Document, mStream)
        mStream.Position = 0
        Response.ClearContent()
        Response.ClearHeaders()

        Response.ContentType = "application/pdf"
        Response.BinaryWrite(mStream.ToArray())
        Response.End()
    End Sub
COSI FUNZIONA :sexpulp: