Hi Eugenio,

try omitting the questing mark in the delete parameter statement:
instead of:
//
// oleDbDeleteCommand1
//
this.oleDbDeleteCommand1.CommandText = "DELETE FROM texto WHERE id_texto=?";
this.oleDbDeleteCommand1.Parameters.Add(new System.Data.OleDb.OleDbParameter("?id_texto",System.Data.OleDb.OleDbType.Integer, 0, "id_texto"));

try:
//
// oleDbDeleteCommand1
//
this.oleDbDeleteCommand1.CommandText = "DELETE FROM texto WHERE id_texto=?";
this.oleDbDeleteCommand1.Parameters.Add(new System.Data.OleDb.OleDbParameter("id_texto",System.Data.OleDb.OleDbType.Integer, 0, "id_texto"));

Regards, Soenke