Access problem

Hej jeg har et problem med min access database, jeg bliver ved med at få følgende fejl:
System.InvalidOperationException: ExecuteReader requires an open and available Connection. The connection's current state is closed.
  at System.Data.OleDb.OleDbConnection.CheckStateOpen(String method)
  at System.Data.OleDb.OleDbCommand.ValidateConnection(String method)
  at System.Data.OleDb.OleDbCommand.ValidateConnectionAndTransaction(String method)
  at System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method)
  at System.Data.OleDb.OleDbCommand.ExecuteReader(CommandBehavior behavior)
  at System.Data.OleDb.OleDbCommand.ExecuteReader()
  at GetIngrediensService.GetIngrediens(String prefix, Int32 maxResults) in c:\Documents and Settings\Kenneth\Dokumenter\Visual Studio 2005\WebSites\ShoppingAssistant\App_Code\GetIngrediensService.cs:line 31

Kode:


public string[] GetIngrediens(string prefix, int maxResults) {
        string[] items = new string[maxResults];
       
        OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OleDB.4.0; Data Source=" + Server.MapPath("App_Data/ShoppingAssistant.mdb"));

        OleDbCommand cmd = new OleDbCommand("SELECT [Ingrediensen] FROM Ingrediens WHERE [Ingrediensen] LIKE '" + prefix + "*' ORDER BY [Ingrediensen];", conn);
       
        conn.Open();
        OleDbDataReader reader = cmd.ExecuteReader(); //LINIE 31!!!
        int i = 0;
        while (reader.Read())
        {
            if (i >= maxResults)
                break;
            items[i] = reader.GetString(0);
            i++;
        }
        conn.Close();
        return items;
    }