[xwiki-users] Error saving pages using XWord

Hi All, I need to give my users the possibility to edit XWiki Pages using XWord but doing some tests I get some errors. I'm using XE 2.4.3 and Microsoft Office 2007. When i create a new page and upload it, XWord works fine but when I try to edit an existing page I get errors while saving the document. Any idea about this problem? I can't see errors on xwiki.log file... Thanks! Loris