C# Button

I have a button on a C# form that requires a double click to fire off the 
btnSubmit_Click event. Is this a bug in VS 2005?

using System;
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

namespace SalesOrderProgress
{
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            //int t = 0;

            btnSubmit.ID = "btnSubmit";
            lblTime.Text = System.DateTime.Now.ToString();
        }

        private void bindGridView()
        {
            clsDataAccess da=new clsDataAccess();

            Session["strSQL"] = "Exec sopGetProductionHeaderbySales '" + 
txtSalesOrder.Text + "','" + txtPosNo.Text + "','" + txtSalesOrder2.Text +

"','" + txtItem.Text + "','" + txtCustomer.Text + "'";
            Session["SalesOrder"] = txtSalesOrder.Text;

            //DataSet dsSalesProgress = new DataSet();
            //SqlDataAdapter daSalesProgress = new 
SqlDataAdapter(Session["strSQL"].ToString(), 
System.Configuration.ConfigurationManager.AppSettings["MC_Baan_Sql"]);
            //SqlCommandBuilder cmdBldr = new 
SqlCommandBuilder(daSalesProgress);
            //daSalesProgress.Fill(dsSalesProgress);
            //gvSalesProgress.DataSource = dsSalesProgress; 08/01/2007 DOB
2 
different methods to create the dataset

            gvSalesProgress.DataSource = 
da.RunSQLWithDataSet(Session["strSQL"].ToString(), 
System.Configuration.ConfigurationManager.AppSettings["MC_Baan_Sql"]);    
 
            gvSalesProgress.DataBind();
            buildPrintCriteria();

            if (gvSalesProgress.PageCount > 0)
            {
                lblNoRecords.Visible = false;
                gvSalesProgress.Visible = true;
            }
            else
            {
                lblNoRecords.Text = "No records found for " + 
txtSalesOrder.Text;
                lblNoRecords.Visible = true;
                gvSalesProgress.Visible = false;
            }
        }

        protected void btnSubmit_Click(object sender, EventArgs e)
        {
            
           try
           {
            lblNoRecords.Visible = false;
            txtCustomer.Text = "";
            txtItem.Text = "";
            
            if (txtPosNo.Text != "" && txtSalesOrder.Text == "")
            {
                lblError.Visible = true;
                lblError.Text = "<p>Please enter a sales order for this 
position</p>";
            }
            else if (txtSalesOrder.Text == "")
            {
                lblError.Visible = true;
                lblError.Text = "<p>Please enter a sales order</p>";
            }
            else
            {
                bindGridView();
            }
           }
           catch(Exception ex)
               {
                   HttpContext.Current.Session["errText"] = ex.Message;
                   throw new Exception("An exception occured in 
btnSubmit_Click", ex);
               }
        }

        protected void btnSubmit2_Click(object sender, EventArgs e)
        {

            try
            {
                lblNoRecords.Visible = false;
                txtSalesOrder.Text = "";
                txtSalesOrder2.Text = "";
                txtPosNo.Text = "";

                if (txtCustomer.Text == "" && txtItem.Text == "")
                {
                    lblError.Visible = true;
                    lblError.Text = "<p>Please enter an Item or
Customer</p>";
                }
                else
                {
                    bindGridView();
                }
            }
            catch (Exception ex)
            {
                HttpContext.Current.Session["errText"] = ex.Message;
                throw new Exception("An exception occured in 
btnSubmit2_Click", ex);
            }
        }

        protected void gvSalesProgress_PageIndexChanging(Object sender, 
GridViewPageEventArgs e)
        {
            gvSalesProgress.PageIndex = e.NewPageIndex;
            bindGridView();
        }

        protected void btnPrint_Click(object sender, EventArgs e)
        {
            Response.Redirect("Printable.aspx?SalesOrder=" + 
Session["SalesOrder"] + "&PosNo=" + Session["PosNo"]);
        }

        private void buildPrintCriteria()
        {
            Session["Criteria"] = "";

            if (txtSalesOrder.Text != "" && txtSalesOrder2.Text != "")
            {
                Session["Criteria"] = " Sales Orders Between <b>" + 
txtSalesOrder.Text + "</b> and <b>" + txtSalesOrder2.Text + "</b>";
            }

            if (txtSalesOrder.Text != "" && txtSalesOrder2.Text == "")
            {
                Session["Criteria"] = " Sales Order <b>" + 
txtSalesOrder.Text + "</b>";
            }

            if (txtItem.Text!= "")
            {
                Session["Criteria"] = " Item <b>" + txtItem.Text + "</b>";
            }

            if (txtCustomer.Text != "")
            {
                Session["Criteria"] = " Customer <b>" + txtCustomer.Text +

"</b>";
            }

        }
    }
}