DataGrid not showing up

[Jim Donahue]

I created a timed event handler to update a Windows DataGrid. After the event handler fires, only the first row of the datagrid shows up (the row with the *). My code is simple and straightforward but I'd appreciate any help on why my datagrid doesn't show my other columns:

public MainForm() {
// Required for Windows Form Designer InitializeComponent();

myTimer.Elapsed+= new ElapsedEventHandler(OnTimedEvent);
myTimer.Interval= 2000;
myTimer.Enabled=true;
myTimer.Start();
}

public void OnTimedEvent(object source, ElapsedEventArgs e) {
myTimer.Stop();
DataSet myDS= GetActiveAlerts();
if( myDS!=null ) {
this.MainGrid.SetDataBinding(myDS,"AM");
this.MainGrid.Expand(-1);
this.MainGrid.Update(); this.MainGrid.Refresh(); }
myTimer.Start();
}

I know the dataset is returning the proper info. Again, all I see is the * column of the datagrid...it has the correct # of rows but no others columns appear.
Thanks!