@ChuckBurgess Its a true fact :)
EDIT: Not sure why the negative vote. While it may not apply exactly in this case, it is worth mentioning. This is exactly what php.net says: http://www.php.net/manual/en/ini.core.php#ini.post-max-size.
If the size of post data is greater
than post_max_size, the $_POST and
$_FILES superglobals are empty.
Negative vote was not mine. Sorry. I'll try what you said when I will have time. For the moment I gave up. Thank you.
The problem is your post_max_size is the same size as upload_max_filesize which will cause the $_FILES array (and $_POST) to be empty. If you up the limit on the post_max_size, the $_FILES array will no longer be empty.