Here is an implementation that does not have that unwanted behaviour:

void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
 if (this.dataGridView1.CurrentCell.ColumnIndex == this.ColumnPersonTypeCode.Index)
 {
  BindingSource bindingSource = (BindingSource)this.dataGridView1.DataSource;
  PersonsDataSet.PersonRow person = (PersonsDataSet.PersonRow)((DataRowView)bindingSource.Current).Row;
  PersonsDataSet.PersonTypeDataTable personTypeDataTable = DataSetDac.FindPersonTypes(person);

  DataGridViewComboBoxEditingControl comboBox = (DataGridViewComboBoxEditingControl)e.Control;
  comboBox.DataSource = personTypeDataTable;
  // force the combobox to pick up the correct value.
  comboBox.SelectedValue = person.PersonTypeId;

  comboBox.SelectionChangeCommitted -= this.comboBox_SelectionChangeCommitted;
  comboBox.SelectionChangeCommitted += this.comboBox_SelectionChangeCommitted;
 }
}

I’ll post an updated zip package as soon as i’m able to setup an ftp connection.

EDIT 28/06/2008: I’ve uploaded (and overwritten) the zip file with the modification.

thanks for this, but I found it doens’t work correctly. here is what I did.

1. click on first “persontypecode” dropdown, it is correct.
2. click on second one, and it shows corrrect.
3. click on the first dropdown again, it is good.
4. slick on second one again. the list is wrong, it shows as the first one.
and so on. to 3rd and 4th..etc

PS. don’t change the value for each drop down.

thanks!