IE8 upload file Ajax version

[davide.filippi]

Hi all,
I've some windows xp that join a domain and the browser is IE8. Group policy on browser are active
I've upgrade zimbra 7.x to zimbra 8.0.x and when the domain user go on zimbra (ajax version) and try to upload a file, the form not appears.
If i log in as admin on that machine, with the same browser, it works.
Can you help me please?