title: DataGridViewComboBoxCell Binding - "value is not valid"
body: <p>I'm trying to bind separate ComboBox cells within a DataGridView to a custom class, and keep getting an error</p>
  
  <blockquote>
    <p>DataGridViewComboBoxCell value is not valid</p>
  </blockquote>
  
  <p>I'm currently assigning the data source for the cell to an <code>IList&lt;ICustomInterface&gt;</code> from a Dictionary I've got. Upon setting the data source however, the index for the <code>ComboBoxCell</code> isn't set, so it has an invalid value selected.</p>
  
  <p>I'm trying to figure out how to get it to select a real value, e.g. the 0th item within the list it has been given to remove this error, or find another way to solve the problem. Anyone have any suggestions?</p>