And, the workaround in #25044 is not working,
the code:

header("Location: http://www.php.net/");
header('HTTP/1.1 303 See Other');

or

header("Location: http://www.php.net/");
header('HTTP/1.1 303 See Other', true, 303);

will result same response header:

HTTP/1.0 302 Found
Location: http://www.php.net/

First of all, both of your examples work fine for me and produce the expected results. You did not mention what web server you are using? And exactly what PHP version are you using?

I try to use the lastest snapshots (PHP 5.3 (5.3.0beta2-dev),VC9 x86 Non Thread Safe (2009-Mar-17 13:00:00)),got the same result.

some infomation from phpinfo():
System: 	Windows NT  6.0 build 6001 (Windows Vista Ultimate Edition Service Pack 1) i586
Build Date: 	Mar 17 2009 12:55:17
Compiler:	MSVC9 (Visual C++ 2008)
Architecture: 	x86 
Server API: 	CGI/FastCGI 

CGI section:
Directive	Local Value	Master Value
cgi.discard_path	0	0
cgi.fix_pathinfo	1	1
cgi.force_redirect	0	0
cgi.nph	0	0
cgi.redirect_status_env	no value	no value
cgi.rfc2616_headers	0	0
fastcgi.impersonate	1	1
fastcgi.logging	1	1

webserver is IIS7, PHP run in FastCGI mode(use php-cgi.exe).

I use HttpWatch to catch response header, 
when use code:

<?php
header('HTTP/1.1 303 See Other');
header("Location: http://www.php.net/");
exit;
?>

the status line in response is:

HTTP/1.1 302 Redirect

and when use code:

<?php
header('HTTP/1.1 303 See Other');
exit;
?>

the status line in response is:

HTTP/1.1 303 See Other

When run php-cgi.exe in command line, the result is expected:

D:\project\www>php-cgi ./test.php
Status: 303 See Other
Location: http://www.php.net/
Content-type: text/html; charset=utf-8


test.php:
<?php
header('HTTP/1.1 303 See Other');
header("Location: http://www.php.net/");
exit;
?>

but visit same file throuth browser and webserver (use http://localhost/test.php) will get 302 status code.

when use this test code:
test.php:
<?php
header("Location: http://www.php.net/");
exit;
?>

use broswer to visit http://localhost/test.php, the status line in response is:

HTTP/1.1 302 Redirect

and use php-cgi.exe under commend line get:

D:\project\www>php-cgi ./test.php
Status: 302 Moved Temporarily
Location: http://www.php.net/
Content-type: text/html; charset=utf-8

If change to ISAPI mode(use php5isapi.dll), the result is expected.

<?php
header('HTTP/1.1 303 See Other');
header("Location: http://www.php.net/");
exit;
?>

will got status line:

HTTP/1.1 303 See Other

I have tried using PHP 5.2 (5.2.10-dev), both VC6 x86 Non Thread Safe (2009-Mar-18 00:00:00) and VC6 x86 Thread Safe (2009-Mar-18 00:00:00). And have tried on windows vista and windows server 2008, got the same results:

test code:

code1:
<?php
header('HTTP/1.1 303 See Other');
header("Location: http://www.php.net/");
exit;
?>

code2:
<?php
header('HTTP/1.1 303 See Other');
exit;
?>

code3:
<?php
header("Location: http://www.php.net/");
exit;
?>

the problem only occurs when run php in fastCGI mode(using php-cgi.exe). 
code1 produce status line:
HTTP/1.1 302 Redirect  (expected: HTTP/1.1 303 See Other)
code2 porduct status line:
HTTP/1.1 303 See Other (expected: HTTP/1.1 303 See Other)
code3 product status line:
HTTP/1.1 302 Redirect  (expected: HTTP/1.1 302 Moved Temporarily)


when run php in ISAPI mode(using php5isapi.dll) or run php-cgi.exe under commend line, both test codes will produce expected result.

it seems that something wrong with header("Location: ") with CGI mode...

The issue is probably caused by fastcgi module of web server. The PHP sends proper headers, but it looks like fastcgi module sets status to 302 in case it finds "Location" header.

yep, I think that you're right.
wait for M$ to fix it..

Confirmed, it is a bug in the FastCGI. I will notice you as soon as an update is available.

Bugs in MS crap aren't bugs in PHP -> BOGUS.