Description:
------------
Hi.  I am using a simple upload script to upload files.  It works on many file sizes, but on file sizes > 500 megs i can see the file in the tmp directory reach 400something megs and then it dissappears. 

Reproduce code:
---------------
		if (!is_dir("files/$id"))
		{
			mkdir("files/$id", 0777);
			chmod("files/$id", 0777);
		}
		$uploadfile =  "files/$id/" . $id . "." . $file[count($file) - 1];
		move_uploaded_file($_FILES["thefile"]["tmp_name"], $uploadfile);
		chmod($uploadfile, 0777);

for the php.ini config i have
memory_limit = 20M      
post_max_size = 5124M
upload_max_filesize = 4500M
apache 2.0

Expected result:
----------------
move file to files/id/id

Actual result:
--------------
it makes the directory, but the file is not moved there.  This works for files < 500 megs, why not more?  The only error reported in apache logs are for chmod at the end