C# - Databinding Gives "System.Data.DataRowView" Instead Of Actual Values?

This is my code:

string SQL = "SELECT email FROM members WHERE subscribe=true";
string myConnString = Application["ConnectionString"].ToString();
OleDbConnection myConnection = new OleDbConnection(myConnString);
OleDbCommand myCommand = new OleDbCommand(SQL, myConnection);
myConnection.Open();
OleDbDataAdapter MyAdapter = new OleDbDataAdapter(myCommand);
DataSet ds = new DataSet();
MyAdapter.Fill(ds);
MailsListBox.DataSource = ds;
MailsListBox.DataBind();
GridView1.DataSource = ds;
GridView1.DataBind();
myConnection.Close();

And so it looks:

As you see, the GridView shows the dataset just fine, and the ListBox fails it. What happened? How can I fix it?