Thanks for that info, lordb. I just checked in an update which I think will fix the problem:
http://jqueryjs.googlecode.com/svn/trunk/plugins/form/jquery.form.js When you get a chance, let me know if it works for you. Mike
My form is simplest as possible just the form tag which contain an hidden field form the max file size and the file fild with name="fichier" With the modification proposed the fileupload seems to work, so I has send it here to help other people with the same problem. I tried to execute original jquery.forms code with different security level in IE7 and with medium or low level I have no more error ... but for a working code in all case my modification seem to be good.
