IE requires double click with custom button

Answer 1

I found another more simple solution, just trigger the event "click" on mousedown for this element only:

$("input").mousedown(function() {
    $(this).trigger('click');
})

in order to avoid problems on other browsers, apply this solution to IE only:

if ($.browser.msie && parseInt($.browser.version, 10) > 8) {
    $("#your_file_input").mousedown(function(event) {
        if (event.which == 1) {
            $(this).trigger('click');
        }
    })
}

here's your jfiddle modified, check it on IE 9-10: http://jsfiddle.net/7Lq3k/

Edit: example modified in order to limit the event handling for left click only (see: How to distinguish between left and right mouse click with jQuery for details)