NIS 2011 and Download Intelligence / Download Insight in Opera, Filezilla, etc.

First post, and first question.

When I use Opera or Filezilla for download any file, NIS notifies in its log when I try to open downloaded file, but at the end of downloading process there's no small popup. This popup appears when I use Firefox for downloading. Is it normal that the popup appears only when I use Firefox or IE?