Crystal and oracle

I have this code to generate a report from c# in windows forms

HTML Code:

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ReportDocument prueba =new ReportDocument();
try
{
        prueba.Load(@"..\..\prueba.rpt");
        CrystalDecisions.Shared.TableLogOnInfo tliCurrent;       
      foreach(CrystalDecisions.CrystalReports.Engine.Table tbCurrent in prueba.Database.Tables)
      {
        tliCurrent = tbCurrent.LogOnInfo;                                        tliCurrent.ConnectionInfo.ServerName = "server";                        tliCurrent.ConnectionInfo.UserID = vclave;                                tliCurrent.ConnectionInfo.Password = vclave;                                tliCurrent.ConnectionInfo.DatabaseName = vdb;
        tbCurrent.ApplyLogOnInfo(tliCurrent);
      }
        crvBasic.ReportSource = prueba;
        crvBasic.Zoom(2);}
        catch( LoadSaveReportException Exp )
            {
        MessageBox.Show("No se encuentra la ruta y/o el reporte para ser ejecutado.", "Load Report Error");}
        catch( Exception Exp)
        {
            MessageBox.Show(Exp.Message, "General Error");}

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The problem is:
if the report use a table in oracle, then the app ask me to type servername,password, etc and finally does not work.
But if i only change to a report using SQL SERVER without changing anything: IT WORKS!!!!

Any help?