Steps to reproduce:

• Create a file list page
• Make 3 identical copies of a file, and give the files different names like: 'image1.jpg', 'image2.jpg', 'image3.jpg'
• Use the 'browse for files' link to upload each of the identical files

Expected: Each of the files should upload successfully
Actual: Some files do not trigger an upload and there is no error. After selecting the file the spinner does not appear and no file is uploaded.

There is no identifiable pattern which of the 3 will fail to upload, but it is consistent that always one of them will.

Retested on chrome/firefox where the issue does not appear.