Work with local WebBrowser created in other thread

Hello everybody,

In my MainWindow (Main Thread), I have a Tab Control (without TabItems) that will contain WebBrowsers.

I have create a class (A) with a variable WebBrowser (Windows Form). This class is generated in other thread.

The WebBrowser from the class (A) is created in created in the MainWindow (Main Thread). In the class (A) I use dispatch method to do it.

public class A    
{
	Public WebBrowser WAdvWebBrowser;
	...       
        public void OpenBrowser(string iURL)
        {
		MainWindow.MainWindowInstance.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Normal, (Action)(() =>
                {
                    WAdvWebBrowser = MainWindow.MainWindowInstance.AddNewWebBrowser(); //In the MainWindow is created the Webrowser
                }));
		WAdvWebBrowser.NavigateTo(iURL, ...); 
		//'Function evaluation is disabled because a previous function evaluation timed out' error in WAdvWebBrowser functions

My problem is when I try to work in with the WebBrowser object in the class (A) I get an error (Function evaluation is disabled because a previous function evaluation timed out) in the debugging.

Can somebody help me?

Thank you in advance.