I don't know if this will work for you, but why not.
You can easely use python to send requests as you whish like so:
import urllib
import urllib2
url = 'http://www.someserver.com/cgi-bin/register.cgi'
user_agent = 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'
values = {'name' : 'Michael Foord',
'location' : 'Northampton',
'language' : 'Python' }
headers = { 'User-Agent' : user_agent }
data = urllib.urlencode(values)
req = urllib2.Request(url, data, headers)
response = urllib2.urlopen(req)
the_page = response.read()
From python doc : http://docs.python.org/2/howto/urllib2.html#headers
Try doing the same thing but with empty user_agent and Headers, it worked in my smal test.
Here is the snippet I tested:
import urllib
import urllib2
url = 'http://www.someserver.com/cgi-bin/register.cgi'
user_agent = ''
values = ''
headers = { '' : '' }
data = urllib.urlencode(values)
req = urllib2.Request(url, data, headers)
response = urllib2.urlopen(req)
the_page = response.read()