Mouse click on dom perfomance issues geckofx(embedded win xp sp3)

I need help to point out the bottleneck of my app. I am using geckofx browser control in winforms app, running on winxp sp3. Click event propagate to dom so slow - it might take up to couple seconds. Some log records with nlog

…
2015-03-30 19:05:26.3085 TRACE WM_LBUTTONDOWN
2015-03-30 19:05:27.0585 TRACE DomClick -Gecko.DOM.GeckoButtonElement
…

There is no such problem in win7 - it running fast on it. Here code of my mainform MainForm.cs

 ….
        public MainForm()
        {

            InitializeComponent();
            this.WindowState = FormWindowState.Maximized;
            //catching win messages
            Application.AddMessageFilter(this);

           Gecko.GeckoPreferences.User["layers.accelerate-all"] = true;

            this.Load += MainForm_Load;


        }

        void MainForm_Load(object sender, EventArgs e)
        {
            LogAllEvents();

        }
…

        private void LogAllEvents()
        {
            geckoWebBrowser.WindowSetBounds += (s, e) => { _logger.Trace("WindowSetBounds - " + e.Bounds); };
            geckoWebBrowser.Paint += (s, e) => { _logger.Trace("Paint -" + e.ClipRectangle); };
            geckoWebBrowser.Invalidated += (s, e) => { _logger.Trace("Invalidated -" + e.InvalidRect); };
            geckoWebBrowser.DomClick += (s, e) => { _logger.Trace("DomClick -" + e.Target.ToString()); };
            geckoWebBrowser.DocumentCompleted += (s, e) => { _logger.Trace("DocumentCompleted -" ); };
        }



public bool PreFilterMessage(ref Message m)
        {

                if (m.Msg == WM_LBUTTONDOWN)
                {
                    _logger.Trace("WM_LBUTTONDOWN");
                    return false;
                }
                else
                    if (m.Msg == WM_LBUTTONUP)
                    {
                        _logger.Trace("WM_LBUTTONUP");
                        return false;
                    }
                    else
                        return false;

        }

MainForm.Designer.cs

 …            
    // BrowserHolder
                // 
                this.BrowserHolder.Controls.Add(this.geckoWebBrowser);
                this.BrowserHolder.Dock = System.Windows.Forms.DockStyle.Fill;
                this.BrowserHolder.Location = new System.Drawing.Point(0, 28);
                this.BrowserHolder.Name = "BrowserHolder";
                this.BrowserHolder.Size = new System.Drawing.Size(1180, 554);
                this.BrowserHolder.TabIndex = 2;
                // 
                // geckoWebBrowser
                // 
                this.geckoWebBrowser.Dock = System.Windows.Forms.DockStyle.Fill;
                this.geckoWebBrowser.Location = new System.Drawing.Point(0, 0);
                this.geckoWebBrowser.Name = "geckoWebBrowser";
                this.geckoWebBrowser.Size = new System.Drawing.Size(1180, 554);
                this.geckoWebBrowser.TabIndex = 0;
                this.geckoWebBrowser.UseHttpActivityObserver = false;
     …

BrowserHolder is panel that wrap webbrowser control.

I don’t have any clue what’s going on, cpu usage under 10 percent. Here’s my machine: ms windows embedded POSready 2009 ver2.0 service pack3 Intel Atom D2500 ,1.86 ghz ,1.98 gb of ram Geckofx 16 and 31 –same result – very slow click