Your browser (or OS) might not know what to do with a .CSV file. If you copy the file, then rename it with a .csv extension, can you double-click it and have it open up in the application of your choice? Alternately, if you drag-and-drop it onto the browser, does it launch the same program?
Also, shouldn't the mime-type be "text/csv" rather than an application?
-JD.