Bad Font rendering on Infragistics WinForms controls

Ok! I think I found an example that reproduces the behavior. My application has a splash screen and it seems that this form causes the font to be badly rendered. The strange thing is that in the past the same splash has never caused troubles. The SplashForm is derived fro a ShadowForm:

public class ShadowForm : Form
    {
        // class style that adds a shadow to the form
        private const int CS_DROPSHADOW = 0x00020000;

        public ShadowForm()
        {
        }

        protected override CreateParams CreateParams
        {
            [SecurityPermission(SecurityAction.LinkDemand, UnmanagedCode = true)]
            get
            {
                CreateParams parameters = base.CreateParams;

                if (DropShadowSupported)
                {
                    parameters.ClassStyle = (parameters.ClassStyle | CS_DROPSHADOW);
                }
                return parameters;
            }
        }

        /// <summary>
        /// Gets if drop shadow is supported by the OS.
        /// </summary>
        public static bool DropShadowSupported
        {
            get
            {
                return IsWindowsXPOrAbove;
            }
        }

        /// <summary>
        /// Gets if OS is Windows XP or above.
        /// </summary>
        public static bool IsWindowsXPOrAbove
        {
            get
            {
                OperatingSystem system = Environment.OSVersion;
                bool runningNT = system.Platform == PlatformID.Win32NT;

                return runningNT && system.Version.CompareTo(new Version(5, 1, 0, 0)) >= 0;
            }
        }
    }

The call from the program.cs is:

static class Program
    {
        //private static Form _splash = null;
        private static Splash _splash = null;
        private static Form1 _mainform = null;
        private static ApplicationContext _context = null;

        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);

            _mainform = new Form1();
            _context = new ApplicationContext();
            Application.Idle += new EventHandler(OnApplicationIdle);
            //_splash = new Form();
            _splash = new Splash();
            _splash.Show();
            Application.Run(_context);
        }

        static void OnApplicationIdle(object sender, EventArgs e)
        {
            if (_context.MainForm == null)
            {
                Application.Idle -= OnApplicationIdle;
                _mainform.PreLoad();

                _splash.Close();
                _splash.Dispose();
                _splash = null;

                _context.MainForm = _mainform;

                _context.MainForm.Show();
            }
        }
    }

If I use a standard form the strings on the menu of the UltraToolbarsManager are well rendered, if I use a Splash form the font they are ugly. If it helps I can e-mail you the VS2008 solution.

Alessandro