Resume downloads with download managers... headers

[phntje]

<?php
$link = "http://host.com/link.rar";
$baselink = basename($link);
$time = time();
$date = date("D, d M Y H:i:s \G\M\T" , $time);
header("Content-Disposition: attachment; filename=$baselink");
header('Expires: '.gmdate("D, d M Y H:i:s", mktime(date("H")+2, date("i"), date("s"), date("m"), date("d"), date("Y"))).' GMT'); 
header("Content-Description: File Transfer");
header("Content-Type: application/octet-stream");
header("Accept-Ranges: bytes");

$sizeheaders = get_headers($link, 1);
$size = $sizeheaders["Content-Len gth"];
    if(isset($_SERVER['HTTP_RANGE']))
    {
        list($a, $range)=explode("=",$_SERVER['HTTP_RANGE']);
        //if yes, download missing part
        str_replace($range, "-", $range);
        $size2=$size;
        $new_length=$size2-$range;
        header("HTTP/1.1 206 Partial Content");
        header("Status: 206 Partial Content");
        header("Content-Le ngth: $new_length");
        header("Content-Range: bytes $range$size2/$size");
    }
    else
    {
        $size2=$size;
        //header("Content-Range: bytes 0-$size2/$size");
        header("Content-Le ngth: ".$size2);
    } 

@readfile($link);
?>

 

Downloading in firefox & other browsers is okay. But when using downloadmanagers, then its downloading the file but the file is corrupt, it's 1 or 2 bytes bigger then the original file.

How to fix this?