how to call BAPI_XMI_LOGON and BAPI_XBP_JOB_START_IMMEDIATELY in a single session/transaction ?

Hi,

I tried the following code to execute a scheduled job immediately.

  RfcSessionManager.BeginContext(destination); 

  IRfcFunction rfcFunc = repository.CreateFunction("BAPI_XMI_LOGON");
  rfcFunc.SetValue("extcompany","testC");
  rfcFunc.SetValue("extproduct","testP");
  rfcFunc.SetValue("interface","XBP");
  rfcFunc.SetValue("version","3.0");

  rfcFunc.Invoke(dest);

  rfcFunc = repository.CreateFunction("BAPI_XBP_JOB_START_IMMEDIATELY");
  rfcFunc.SetValue("jobname","MYSCHEDULEDJOB");
  rfcFunc.SetValue("jobcount","15530600");
  rfcFunc.SetValue("external_user_name","username");

  rfcFunc.SetValue("target_server","devsapsystem");
  rfcFunc.Invoke(dest);

   RfcSessionManager.EndContext(destination);

But I got the message "Internal problem (function BAPI_XBP_JOB_START_IMMEDIATELY)" in BAPIRet2 output. All parameters passed are correct.

How can I resolve this error ?