ParentRelations.Add() desn't work from time to time ...

I have some problem with binding two tables in DataGrid control.

when I run my code when TEST ( SIMULATE ) is active it works perfect.
when I switch to real system it doesn't work, the code has deadlock in placed marked as "DeadLock heare"
my english is poor, so please have a look on my part of code.

Code:

---

public class Form1 : System.Windows.Forms.Form
{
  ...

  private void ShowLogsValue()
  {
    // for Test only, DataTable is loaded with some random data
    if ( SIMULATE_ACTIVE )
    {
      m_threadLoadData = new Thread ( new ThreadStart( oradb.GetLogsORAData_TEST ));
      m_threadLoadData.Name = "LOAD_DATA";
      m_threadLoadData.Start();
      m_threadLoadData.Join();
      this.Binde2Tables();
      return;
    }

    // real process, DataTable is loaded by OdbcDataReader Read() method
    m_threadLoadData = new Thread(new ThreadStart( oradb.GetLogsORAData ));
    m_threadLoadData.Name = "LOAD_DATA";
    m_threadLoadData.Start();
    m_threadLoadData.Join();
    this.Binde2Tables();
  }

  public void Binde2Tables()
  {
    DataRelation myDataRelation;
    DataColumn parentColumn;
    DataColumn childColumn;
    parentColumn = oradb.dsLogsORA.Tables["LogsOracle"].Columns["LogID"];
    childColumn = oradb.dsLogsORA.Tables["LogsOracleData"].Columns["LOGS_ID"];
    myDataRelation = new DataRelation("WartościLogu", parentColumn, childColumn);
    oradb.dsLogsORA.Tables["LogsOracleData"].ParentRelations.Add(myDataRelation);
    m_dGrid1.SetDataBinding(oradb.dsLogsORA,"LogsOracle");
  }

...
}

public class OraDB
{

  public void GetLogsORAData()
  {
    while ( myReader.Read() )
    {
      ...
    }
   
    DeadLock here
    myReader.Close();
    ....
  }


  public void GetLogsORAData_TEST()
  {
    // for Test only, to consume some CPU time
      for(int i = 0; i <= 99999999; i ++)
      {
        test ++;
      }
      ...
  }
 
}    ....

---

Could you please help me with this bug ?

Thanks in advance

Andrzej Falk