UIPickerView display properly in iPhone simulator, but not in real device (iPhone 5s)

Hi, As title said, I create an UIPickerView to show in a UIViewController. In iPhone simulator all work (3.5" device and 4" device), but on real device (iPhone 5s) the data are showing on the left side and it's visible only a part of the data. I tried in debug mode and release mode. It doesn't seem the same problem described here: http://forums.xamarin.com/discussion/13038/uipickerview-fine-in-debugger-but-displays-wrong-on-ipad/p1 because the user has no problem if he use release mode.

My UIPicker use a subclass of a UIPickerViewModel. My code:

public class CodServicePickerModel : UIPickerViewModel { private List items;

private float heightForRow; private float widthForRow;

public CodServicePickerModel(List items, float widthForRow, float heightForRow) { this.items = items; this.heightForRow = heightForRow; this.widthForRow = widthForRow - 10f; }

public override int GetComponentCount (UIPickerView picker) { return 1; }

public override int GetRowsInComponent (UIPickerView picker, int component) { if (items == null || items.Count < 1) { return 1; } return items.Count; }

public override UIView GetView (UIPickerView picker, int row, int component, UIView view) {

  if (view == null && component == 0) {
      view = new UIView (new RectangleF (0, 0, GetComponentWidth (picker, component), GetRowHeight (picker, row)));
      var labelCod = new UILabel (new RectangleF (10f, 0, view.Frame.Width - 10f, view.Frame.Height / 2));
      labelCod.TextColor = ViewConstant.getTextVeryDark ();
      ViewUtility.setSize (labelCod, ViewConstant.littleText);
      labelCod.Text = "Cod. Servizio " + items [row].codiceServizio;

      view.Add (labelCod);
      var labelIndirizzo = new UILabel (new RectangleF (10f, labelCod.Frame.Height, view.Frame.Width - 10f, view.Frame.Height / 2));
      labelIndirizzo.TextColor = ViewConstant.getTextLightColor ();
      ViewUtility.setSize (labelIndirizzo, ViewConstant.microText);
      labelIndirizzo.Text = items [row].indirizzoCompleto;
      view.Add (labelIndirizzo);
  }
  return view;

}

public override float GetRowHeight (UIPickerView picker, int component) { return heightForRow; }

public override float GetComponentWidth (UIPickerView picker, int component) { if (component == 0) { return widthForRow; } return 0; } }

Any ideas?