private void btnLkpCondPagamento_Click(object sender, EventArgs e)
{
if (this.bdCondicaoDePagamento.ShowDialog() == DialogResult.OK)
{
cdp_cod.Text = Convert.ToString(sysPedidoCompraCondicaoDePagamento1.cdp_cod);
cdp_descr.Text = Convert.ToString(sysPedidoCompraCondicaoDePagamento1.cdp_descr);
}
}

But have a error :  The CurrentRow could not be evaluated because the CurrentRowIndex is out of range.  Business object record count: 0.  CurrentRowIndex: -1.

public System.Int32 cdp_cod
{
get
{
object loValue;
loValue = this.CurrentRow["cdp_cod"];
if (loValue == DBNull.Value)
{
return 0;
}
else
{
return (System.Int32)loValue;
}
}
set
{
this.CurrentRow["cdp_cod"] = value;
}
}

I think it is going to be hard to tell you "why", without knowing how you are fetching your data. The thing is, at the point you are getting an error, your BO is empty. Have a look at your fill methods and that might give you some clues.