Property Grid -- Editor ellipsis dont show with a dropdown list

Question

In a property grid, I have implemented for a property both a StringConverter to display a list of values and a UITypeEditor to open a form for editing.

Each work well separately. However, when I put both of them together, StringConverter and the UITypeEditor, I dont see the ellipsis to edit my property. The ellipsis is hidden below the arrow of the dropdown.

Any idea?

Code below -- if that helps

       [Editor(typeof(VideoDeviceEditor), typeof(UITypeEditor))]
    [TypeConverter(typeof(VideoDevicesList))]
    public class VideoDevices
    {

    }
    public class VideoDevicesList : System.ComponentModel.StringConverter
    {
        public override System.ComponentModel.TypeConverter.StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
        {
            ChannelPropertyConfiguration inst = (ChannelPropertyConfiguration)context.Instance;
            List<string> lgs = new List<string>();

            lgs.Add("Microsoft Life Cam");
            lgs.Add("Logitech Web Cam");

            return new StandardValuesCollection(lgs);
        }
        public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
        {
            return true;
        }
        public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)
        {
            return true;
        }
    }

    public class VideoDeviceEditor : UITypeEditor
    {
        public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
        {
            return UITypeEditorEditStyle.Modal;
        }
        public override object EditValue(ITypeDescriptorContext context, System.IServiceProvider provider, object value)
        {
            IWindowsFormsEditorService svc = provider.GetService(typeof(IWindowsFormsEditorService)) as IWindowsFormsEditorService;
            if (svc != null)
            {
                MessageBox.Show("OK");
            }
            return value;
        }
    }