"Download all" in Privates files failed with javascript error (IE 8 & 9)

When using IE (tested with version 8 & 9), users cannot use the "Dowload all" button in the Privates files. They got a javascript error "invalid argument" instead of the usual download pop-up. This works well however with Firefox or Chrome.

Replication steps:

1. User is admin
2. Add a private files block
3. Click "Manage my privates files"
4. Upload a file
5. Click button "Download all"

The progress icon appear but seem to reset in loop.

A javascript error icon shows up in the corner, with this detail:

Détails de l'erreur de la page Web

Agent utilisateur : Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; InfoPath.1; .NET CLR 1.1.4322; .NET4.0C; .NET4.0E; BRI/2)

Horodateur : Fri, 3 Feb 2012 21:42:17 UTC

(the error bellow occur many time in loop)

Message : Argument non valide.

Ligne : 15

Caractère : 168

Code : 0

URI : http://xyz.com/lib/javascript.php?file=%2Flib%2Fform%2Ffilemanager.js&rev=479