FileDownloader does not work with ExternalResource

I want to download a file from an external server via clicking on a button. My code looks something like this:

...
Button button = new Button( "My Button" );
FileDownloader loader = new FileDownloader( new ExternalResource( "http://..." ) );
loader.extend( button );
..

But it does not work (if I use
BrowserWindowOpener
instead of
FileDownloader
everything works fine). It happens nothing (no logging, no errors, just nothing) when I click on the button. I also debugged the client side. Everything looks fine, the method
onClick()
in
FileDownloaderConnector
is called and does its work but the browser does not open the download window (I tried it with firefox and chrome).
What is the problem? Is it not possible to use
ExternalResource
, or…
Is there a workaround to download files in another way?

Thanks!

Hi Philip, have you resolved the problem? I realised, that problem is with files, that displays in browser. So in my case archives, xls, doc files work, but pdf, txt, gif don’t work.
Have you found solution or workaround?