http access produces 503

[Rog]

I am porting a simple code from Perl, the website asks for usr/pwd and
the server's side Perl script makes atemp ftp dir for file upload.

The original Perl script connects okay, does its job. The same URL
stuffed into FF3 performs the same way.
My Python script I am sweating out for past four days (noob!) gets
consistently "503", even with user agen set to: Mozilla/5.0 (Windows;
U; Windows NT 5.1; it; rv:1.8.1.11) Gecko/20071127 Firefox/2.0.0.11.
Snippets of relevant code below.

Please, help me understand how this same code lets me log in into my
router usr/pwd running .asp, but this !@#$% perl script returns to me
w/503 c*ap?
Thank you.

Do I need to set any proxy? The server is on intranet and the FF3 is
set to proxy. The original Perl script did not use any proxy setting.

<pre>

url = http://example.com/ftpsetup.pl?username=boofa&nodeid=42
#########################################################
# create a password manager
    password_mgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
# Add the username and password.
# If we knew the realm, we could use it instead of ``None``.
    password_mgr.add_password(None, url, uid, pcode)
    handler = urllib2.HTTPBasicAuthHandler(password_mgr)
    class Mopener(URLopener): version = "Mozilla/5.0 (Windows; U;
Windows NT 5.1; it; rv:1.8.1.11) Gecko/20071127 Firefox/2.0.0.11"

    opener = Mopener()

# create "opener" (OpenerDirector instance)

    opener = urllib2.build_opener(handler)
    opener.addheaders = [('User-agent', 'Mozilla/5.0 (Windows; U;
Windows NT 5.1; it; rv:1.8.1.11) Gecko/20071127 Firefox/2.0.0.11')]

    opener.version = "Mozilla/5.0 (Windows; U; Windows NT 5.1; it; rv:
1.8.1.11) Gecko/20071127 Firefox/2.0.0.11"

    print opener.version
# timeout in seconds
    timeout = 10
    socket.setdefaulttimeout(timeout)

# Install the opener all calls to urllib2.urlopen use our opener.
    urllib2.install_opener(opener)

    try:
        response = opener.open(url)
        # "http://www.useragent.org/" tested okay!!!
        print"ok = 1"
    except:
        print "error 1"
#####################################################################################

output from the above:

Mozilla/5.0 (Windows; U; Windows NT 5.1; it; rv:1.8.1.11) Gecko/
20071127 Firefox/2.0.0.11
error 1
Error code:  503
('Service Unavailable', 'The server cannot process the request due to
a high load')
</pre>