I doubt LWP is sending anything 'wrong'. It's far more likely that the server is checking the user agent. Fortunately, LWP and related HTTP::Header and HTTP::Response objects are eminently scriptable. You can set headers to whatever you'd like.

To see all headers and values, use HTTP::Header's scan() method.

#!/usr/bin/perl 
use strict;
use LWP::UserAgent;
my  $agent = LWP::UserAgent->new;
my  $headers = HTTP::Headers->new('User_Agent' => 'Cyberdog/5.0',
                              'Accept' => 'image/gif, 
                               image/x-xbitmap,
                               image/png,
                               image/jpeg,
                               */*',
                               'Accept-Charset' => 'iso-8859-1',
                               'Accept-Language' => 'en-US');

#headers before the request:
    $headers->scan(\&printheaders);
 my $response = $agent -> get('http://localhost', $headers);
#and after: 
    $response->scan(\&printheaders);

sub printheaders() {
    my $h = shift;
    my $v = shift;
    print ("Header: $h \t Value:$v\n");
}
[download]

You can clear all headers using HTTP::Headers' clear() method, but I don't think it's what you want.