title: Devexpress gridview problem
body: <p>when i access on database before binding the gridview 
  the gridview never binding again 
  here some code:</p>
  
  <pre><code>    void Page_Load(object sender, EventArgs e)
  { 
      if (!IsPostBack)
      {
          date.Date = DateTime.Now;
          string mode = Request.Params["mode"].ToString().ToLowerInvariant();
          lblPatientName.Text= Session["PatientName"].ToString();
          switch (mode)
          {
              case "new":
                  {
                      Page.Title = "Add New Patient Visit";
  
                      Session["visitID"] = System.Guid.NewGuid();
  
                      //get basic data (countrycode,cityCode,districtCode,areaCode) from patientdata table
                      SqlParameter pra = new SqlParameter("@Patientid", Session["PatientID"].ToString());
                      SqlDataReader dr = SqlHelper.ExecuteReader(ConfigurationManager.ConnectionStrings["NetCareConnectionString"].ConnectionString,
                             "PatientPrescriptionInsertPrepare", pra);
  
                      if (dr.Read())
                      {
                          SqlParameter[] prm = new SqlParameter[7];
  
                          prm[0] = new SqlParameter("@visitID", Session["visitID"].ToString());
                          prm[1] = new SqlParameter("@Patientid", Session["PatientID"].ToString());
                          prm[2] = new SqlParameter("@Specialization", Session["special"].ToString());
                          prm[3] = new SqlParameter("@countrycode", dr["CountryCode"].ToString());
                          prm[4] = new SqlParameter("@cityCode", dr["CityCode"].ToString());
                          prm[5] = new SqlParameter("@districtCode", dr["DistrictCode"].ToString());
                          prm[6] = new SqlParameter("@areaCode", dr["AreaCode"].ToString());
                          SqlHelper.ExecuteNonQuery(CommandType.StoredProcedure, "PreparePrescrption", prm);
                      }
  
                  }
                  break;
          }
  
      }
  }  
  </code></pre>
  
  <p>when i use the event to binding the grid nothing happen when i remove the code upper there every thing run fine:</p>
  
  <pre><code> protected void btnAdd_Click(object sender, EventArgs e)
  {
  
      SqlParameter [] prm = new SqlParameter[3];
      prm[0] = new SqlParameter("@visitID", Session["visitID"].ToString());
      prm[1] = new SqlParameter("@Patientid", Session["PatientID"].ToString());
      prm[2] = new SqlParameter("@examinationcode", Session["Examinationcode"].ToString());
      SqlHelper.ExecuteNonQuery(CommandType.StoredProcedure, "PatientExaminations_insert", prm);
      gvParientInvs.DataBind();
  }
  </code></pre>