Need help with Listbox updating

I have a wierd problem. I have made a copy/paste from one of my programs that finns a datagrid with values from a sql db. And it works fine in that example, but when I use the same code with the oledb and an access db I get an error... here is the code for the updatecommand

protected void DataGrid1_UpdateCommand(object source, DataGridCommandEventArgs e)
       {
                           
           OleDbConnection myConn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\inetpub\wwwroot\webreport\userdb.mdb");
           

           OleDbCommand cmd = new OleDbCommand("Update",myConn);
           cmd.CommandType = CommandType.StoredProcedure;  
           
           
           OleDbParameter param = new OleDbParameter();
           
           
           
           
           string userid = DataGrid1.DataKeys[e.Item.ItemIndex].ToString();
           param = cmd.Parameters.Add("@puserid",OleDbType.varchar);
           param.Direction = ParameterDirection.Input;
           param.Value = userid;
           
           string username = ((TextBox)e.Item.Cells[1].Controls[0]).Text; 
           param = cmd.Parameters.Add("@pusername",OleDbType.VarChar);
           param.Direction = ParameterDirection.Input;
           param.Value = username;
           
           string password = ((TextBox)e.Item.Cells[2].Controls[0]).Text; 
           param = cmd.Parameters.Add("@ppassword",OleDbType.VarChar);
           param.Direction = ParameterDirection.Input;
           param.Value = password;

           string admin = ((TextBox)e.Item.Cells[3].Controls[0]).Text; 
           param = cmd.Parameters.Add("@padmin",OleDbType.Boolean);
           param.Direction = ParameterDirection.Input;
           param.Value = System.Convert.ToBoolean(admin);
           
       



           cmd.Connection.Open();
           cmd.ExecuteNonQuery();
           cmd.Connection.Close();
           DataGrid1.EditItemIndex = -1;
           BindGrid();
           
       }

The error occurs on the line

string userid = DataGrid1.DataKeys[e.Item.ItemIndex].ToString();

and the error is:

Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index

The only thing I can think of is that primary keys are different in Access and SQL... other than that there is no difference between the code...

The stored procedure looks like:

UPDATE reportusers SET username = [@pusername], [password] = [@ppassword], admin = [@padmin]

WHERE userid=[@puserid];

any help would be nice! This is a wierd problem...

kind regards

Henrik

[edit]changed PHP tags for VB tags [/edit]