提交包含2个文件输入字段的表单时无限页面加载

The following code works fine on wamp server, but when I upload it to production server and I submit with 2 small files like 50k, the page loads indefinitely (waited about 10 minutes, timeout on server is 30 sec.), no errors, no nothing. The server runs on linux php version 5.4.16. I suspect that the problem is a setting in php.ini but can't find it.

<?php
    var_dump($_FILES['small_image']);
    var_dump($_FILES['big_image']);
?>
<html>
<head>
    <title>upload</title>
</head>
<body>
<form action="" method="post" enctype="multipart/form-data">
    <input type="file" name="small_image">
    <input type="file" name="big_image">
    <input type="submit" value="Upload">
</form>
</body>
</html>

Update: The problem was with a third party program (cyberoam) in the network, somehow blocked the upload.

Check if you are allowed to submit files. Create a php file with

<?php
phpinfo();
?>

and check it. If you are not allowed, create a file called "php.ini" in your web folder with theses lines:

php_value upload_max_filesize 10M
php_value post_max_size 20M
php_value memory_limit 32M