Web browser control emulation issue (FEATURE_BROWSER_EMULATION)

Below is my WebBrowser playground application (in C#) which works well with your URL (http://demos.dojotoolkit.org/demos/calendar/demo.html).

Disabling FEATURE_NINPUT_LEGACY_MODE is what made the difference, I believe. There is a couple of other settings I enabled, as well. It also shows how to use HKEY_CURRENT_USER instead of HKLM, so the app doesn’t require admin rights.

using Microsoft.Win32;
using System;
using System.ComponentModel;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WebBrowserApp
{
    public partial class MainForm : Form
    {
        const int POLL_DELAY = 250;
        WebBrowser _webBrowser;

        // set WebBrowser features, more info: http://stackoverflow.com/a/18333982/1768303
        static void SetWebBrowserFeatures()
        {
            // don't change the registry if running in-proc inside Visual Studio
            if (LicenseManager.UsageMode != LicenseUsageMode.Runtime)
                return;

            var appName = System.IO.Path.GetFileName(System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName);

            var featureControlRegKey = @"HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\FeatureControl\";

            Registry.SetValue(featureControlRegKey + "FEATURE_BROWSER_EMULATION",
                appName, GetBrowserEmulationMode(), RegistryValueKind.DWord);

            // enable the features which are "On" for the full Internet Explorer browser

            Registry.SetValue(featureControlRegKey + "FEATURE_ENABLE_CLIPCHILDREN_OPTIMIZATION",
                appName, 1, RegistryValueKind.DWord);

            Registry.SetValue(featureControlRegKey + "FEATURE_AJAX_CONNECTIONEVENTS",
                appName, 1, RegistryValueKind.DWord);

            Registry.SetValue(featureControlRegKey + "FEATURE_GPU_RENDERING",
                appName, 1, RegistryValueKind.DWord);

            Registry.SetValue(featureControlRegKey + "FEATURE_WEBOC_DOCUMENT_ZOOM",
                appName, 1, RegistryValueKind.DWord);

            Registry.SetValue(featureControlRegKey + "FEATURE_NINPUT_LEGACYMODE",
                appName, 0, RegistryValueKind.DWord);
        }

        static UInt32 GetBrowserEmulationMode()
        {
            int browserVersion = 0;
            using (var ieKey = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\Internet Explorer",
                RegistryKeyPermissionCheck.ReadSubTree,
                System.Security.AccessControl.RegistryRights.QueryValues))
            {
                var version = ieKey.GetValue("svcVersion");
                if (null == version)
                {
                    version = ieKey.GetValue("Version");
                    if (null == version)
                        throw new ApplicationException("Microsoft Internet Explorer is required!");
                }
                int.TryParse(version.ToString().Split('.')[0], out browserVersion);
            }

            if (browserVersion < 7)
            {
                throw new ApplicationException("Unsupported version of Microsoft Internet Explorer!");
            }

            UInt32 mode = 11000; // Internet Explorer 11. Webpages containing standards-based !DOCTYPE directives are displayed in IE11 Standards mode. 

            switch (browserVersion)
            {
                case 7:
                    mode = 7000; // Webpages containing standards-based !DOCTYPE directives are displayed in IE7 Standards mode. 
                    break;
                case 8:
                    mode = 8000; // Webpages containing standards-based !DOCTYPE directives are displayed in IE8 mode. 
                    break;
                case 9:
                    mode = 9000; // Internet Explorer 9. Webpages containing standards-based !DOCTYPE directives are displayed in IE9 mode.                    
                    break;
                case 10:
                    mode = 10000; // Internet Explorer 10.
                    break;
            }

            return mode;
        }

        // static constructor, runs first
        static MainForm()
        {
            SetWebBrowserFeatures();
        }

        public MainForm()
        {
            InitializeComponent();

            _webBrowser = new WebBrowser() { Dock = DockStyle.Fill };
            this.Controls.Add(_webBrowser);

            this.Size = new System.Drawing.Size(800, 600);
            this.Load += MainForm_Load;
        }

        // start the task
        async void MainForm_Load(object sender, EventArgs e)
        {
            try
            {
                dynamic document = await LoadDynamicPage("http://demos.dojotoolkit.org/demos/calendar/demo.html",
                    CancellationToken.None);

                MessageBox.Show(new { document.documentMode, document.compatMode }.ToString());
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        // navigate and download 
        async Task<object> LoadDynamicPage(string url, CancellationToken token)
        {
            // navigate and await DocumentCompleted
            var tcs = new TaskCompletionSource<bool>();
            WebBrowserDocumentCompletedEventHandler handler = (s, arg) =>
                tcs.TrySetResult(true);

            using (token.Register(() => tcs.TrySetCanceled(), useSynchronizationContext: false))
            {
                this._webBrowser.DocumentCompleted += handler;
                try
                {
                    this._webBrowser.Navigate(url);
                    await tcs.Task; // wait for DocumentCompleted
                }
                finally
                {
                    this._webBrowser.DocumentCompleted -= handler;
                }
            }

            // get the root element
            var documentElement = this._webBrowser.Document.GetElementsByTagName("html")[0];

            // poll the current HTML for changes asynchronosly
            var html = documentElement.OuterHtml;
            while (true)
            {
                // wait asynchronously, this will throw if cancellation requested
                await Task.Delay(POLL_DELAY, token);

                // continue polling if the WebBrowser is still busy
                if (this._webBrowser.IsBusy)
                    continue;

                var htmlNow = documentElement.OuterHtml;
                if (html == htmlNow)
                    break; // no changes detected, end the poll loop

                html = htmlNow;
            }

            // consider the page fully rendered 
            token.ThrowIfCancellationRequested();

            return this._webBrowser.Document.DomDocument;
        }
    }
}