Conflict between multipart/form-data and iso-8859-1

In a Form tag there is a conflict between  enctype="multipart/form-data" and french character set.

The following code:  method="post" enctype="multipart/form-data" accept-charset ="iso-8859-1" allows me to include a file (input type="file") but french characters (accents) are replaced by "?". If I replace the code as follows: method="post" enctype="application/x-www-form-urlencoded"  the french characters works but the input type="file" won't work.

In the update table I have: nom = <cfqueryparam cfsqltype="cf_sql_varchar" value="#wordquoteconvert(nom)#"> I use SQL Express.

Any idea?

Thanks