Vb.net 使用crystal Report加载报告失败

尝试在vb.net应用程序中打印crystal report时，我遇到一个错误（加载报告失败） 但是我的问题是（这个错误并不总是发生）可能在打印了未知数量的报告之后，一旦这个错误发生了

这是我的密码：

    Dim cmd As New OleDbCommand
    Dim connp As New OleDbConnection
    Dim da As New OleDbDataAdapter
    Dim ds As New DataSet
    Dim strsql As String
    Dim strreprotname As String
    Try
        connp.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" & Application.StartupPath & "\report.mdb; Jet OLEDB:Database Password=KNOZ1003"
        connp.Open()
        ds.Reset()
        strsql = "select * from tab3"
        cmd.CommandText = strsql
        cmd.Connection = connp
        da.SelectCommand = cmd
        da.Fill(ds)
        strreprotname = "cashrpt"
        Dim strreportpath As String = Application.StartupPath & "\Reports\" & strreprotname & ".rpt"
        Dim rptdocument As New CrystalDecisions.CrystalReports.Engine.ReportDocument
        Dim prnset As New Printing.PrinterSettings
        Dim pg As New Printing.PageSettings
        rptdocument.Load(strreportpath)
        rptdocument.SetDataSource(ds.Tables(0))
        rptdocument.SetDatabaseLogon("", "", "", Application.StartupPath + "\report.mdb")
        prnset.PrinterName = cashprinter
        rptdocument.PrintToPrinter(prnset, pg, False)
        cmd.Dispose()
        connp.Close()
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try