trouble with file_mime_type() in upload.php

Thanks. As you can see, vnd.ms-excel already exists (first one) in mimes.php:

'xls' => array('application/vnd.ms-excel', 'application/msexcel', 'application/x-msexcel', 'application/x-ms-excel', 'application/x-excel', 'application/x-dos_ms_excel', 'application/xls', 'application/x-xls', 'application/excel', 'application/download', 'application/vnd.ms-office', 'application/msword'),

proof that an old dog can learn new tricks