AJAX get returns empty string - why?

AJAX get returns empty string - why?

Here must be something in my code which I have overseen - but I can't find it...

Using the following line:

        $.get("http://api.jquery.com/api/",function(data) {...});

data is always an empty string when called from within Firefox 3.6.

Everything works fine in Internet Explorer 8 ...

What might be my mistake here?

I'm using jQuery v1.4.2