Passive FTP on Win 2003 Stdandard Server

Hi I have Win 2003 Standard server running FTP server in IIS. My FTP client is Globescape CuteFTP Pro. I need to enable Passive (PASV) access to the FTP site. I can connect successfully using Active(PORT) connection. I have tried the following to enable PASV ftp on the server.

1. Carried out the following
  http://support.microsoft.com/?id=555022. I used port range 5500 tot 5502
2. Opened up the ports 5500 to 5502. First using Port redirection, also tried placing the server on the DMZ
3. Port redirection on ports 20 and 21 to the server.


Symptoms:
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Using a CuteFTP in PASV mode I get the following:

STATUS:>        Getting listing ""...
STATUS:>        Connecting to ftp server xx.xx.xx.xx:21 (ip = xx.x.xx.xx)...
STATUS:>        Socket connected. Waiting for welcome message...
            220 Microsoft FTP Service
STATUS:>        Connected. Authenticating...
COMMAND:>      USER <authorized user>
            331 Password required for <authorized user>.
COMMAND:>      PASS ******
            230 User <authorized user> logged in.
STATUS:>        Login successful.
COMMAND:>      PWD
            257 "/" is current directory.
STATUS:>        Home directory: /
COMMAND:>      FEAT
            211-FEAT
                SIZE
                MDTM
            211 END
STATUS:>        This site supports features.
STATUS:>        This site supports SIZE.
COMMAND:>      REST 100
            350 Restarting at 100.
STATUS:>        This site can resume broken downloads.
COMMAND:>      REST 0
            350 Restarting at 0.
COMMAND:>      PASV
ERROR:>         Timeout (60000 ms) occurred on receiving server response.
ERROR:>         Failed to establish data socket.
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I have also written a custom FTP client program. It also seems to connect succssfully but when issued with ls command to list the folder contents, i get a timeout error.

Does anyone have anyidea why the server is behaving like this? Any help appreciated.
Thanks
Sailr