Sorry, but your problem does not imply a bug in PHP itself.  For a
list of more appropriate places to ask for help using PHP, please
visit http://www.php.net/support.php as this bug system is not the
appropriate forum for asking support questions.  Due to the volume
of reports we can not explain in detail here why your report is not
a bug.  The support channels will be able to provide an explanation
for you.

Thank you for your interest in PHP.

making some tests, notice that the code works on php 4 but 
the problem only seems to happend on php 5.1.2. i used the 
following code for testing:

<?php
$file = 'file.wma';
$tono = 'tono.wma';
$content_length = filesize($file);

header("Content-Type: audio/x-ms-wma"); 
header('Content-Length: '.$content_length);
header('Content-Disposition: filename="'.$tono.'"');
readfile($file);
?>

Solution.

the problem was that for some reason the browser need the 
extension of the file so i solve this using the following on 
the virtual host:

RewriteRule ^/demo/(.+)/(.+)\.wma$ /demo.php?module=$1&id=$2 
[L]

that way the url can be something like /demo/test/file.wma 
and the file can be now download and played.