title: Datagridview column index changing when binding to a datatable
body: <p>i have two datragridviewcomboboxcolumn,and two textbox column in a datagridview.each combobox column is binded to separate binding source.</p>
  
  <p><strong>column names are sl_no,col_empname,col_empworktype,Col_Hours</strong> etc.and 
  displaymember,datapropertyname,valuemember and for comboxcolumn are</p>
  
  <p>col_empname:-emp_name,emp_id,emp_id</p>
  
  <p>col_empworktype:-worktypename,worktypeid,worktypeid</p>
  
  <p>my issues are </p>
  
  <ol>
  <li>when i bind data to gridview it shows a extra column emp_id(image 1)</li>
  <li>when i select the combobox column its column index is changed</li>
  <li>after selecting the combox column it shows an error datagridview
          '<strong>Datagridviewcombobox values is not valid!'</strong></li>
  </ol>
  
  <p><img src="https://i.stack.imgur.com/j8aNS.jpg" alt="enter image description here"></p>
  
  <p>in my form load i have specified datapropertyname</p>
  
  <pre><code>Dim employeecolumn As DataGridViewComboBoxColumn = CType(grdWorkStatus.Columns("Col_EmpName"), DataGridViewComboBoxColumn) 
  employeecolumn.DisplayMember = "emp_name" 
  employeecolumn.ValueMember = "emp_Id" 
  employeecolumn.DataPropertyName = "emp_Id" 
  employeecolumn.DataSource = EmployeeSource 
  </code></pre>
  
  <p>all this issue occur only when i bind data from database to grdiview(Updating grdiview data). Otherwise i am able to save.and evrything is working fine.</p>
  
  <p><img src="https://i.stack.imgur.com/ACzHz.jpg" alt=""></p>
  
  <p>Thanks in Advance.</p>