I've got a user who's while using latest version of OSX and Safari. As he attempts to upload personal files via a form, it dangles (spinner spinning) but nothing happened. Used to do some reasearch and located this:

http://airbladesoftware.com/notes/note-to-self-prevent-uploads-hanging-in-safari

This fixed problems in the past versions of Safari, but clearly not Safari 5.

I'm wondering if other people has any ideas how you can resolve this? There is some pointed out from it being associated with persistent http connections (thus the fix above) and i'm using PHP (however i don't believe that means something).

I have had some success delivering the bond: close header to resolve this problem.

Add

 header("connection: close");

towards the code that handles the file upload. It does not appear to resolve the problem 100% however it certainly enhances it. observe that it's situation sensitive: "Connection: close" will not work.

Well I discovered that during my situation the problem is certainly with respect to the file content. When uploading a specific Digital file it fails in 8 from 10 attempts (Safari 5.5.1, but here's the rarely situation where IE does a more satisfactory job-).

When loading and conveying the Digital file with Mac's Preview developing a new Digital fixes the issue vanishes. Regrettably nothing that can help to repair the problem but maybe worth to provide Safari customers an indication.