jQuery File Upload Internet Explorer issue

jQuery File Upload Internet Explorer issue

I am using the jQuery File Uploader
(http://blueimp.github.io/jQuery-File-Upload/) and it has a problem with
Internet Explorer 9 (Firefox and Chrome are working just fine). Whenever
you click the "Add Files" button for the first couple of times, there is
this 7-10 second lag, as if the whole browser would freeze. After this
lag, the file dialog opens as it should and even the upload functionality
works perfectly. I don't receive any error from the IE Developer Tools
(F12).
This is used for the "Add Files" button:
<input type="file" name="files[]">
Any suggestions or ideas how to troubleshoot this issue?