Asynchronous Question

I'm developing a FTP client application with async. methods. Using delegates and begininvoke. But, still the application doesn't seem to be multithreaded from main GUI's thread cuz during download it halts and the GUI interface blanks out. It returns to normal only after the download has been done. The code doesnt' return to "// other processing stuff //////////" from below till downloading is complete. Thanks, JJ ------------------------- For thsoe who're interested in code: class A { DelegateDownload d = new DelegateDownload (b.Download); d.BeginInvoke(...., ...., ....., ...., new AsyncCallback(b.DownloadCallback); // other processing stuff ////////// } //end of class A class B { public void Download(..., ...., ...., ....) { } public void DownloadCallback(IAsyncResult ar) { } } //end of class B