Using Crypt::SSLeay to post

Hi,

I'm want to use LWP and Crypt::SSLeay to send an XML packet to a secure 
web server then get back and parse a response. I am doing this from 
behind a firewall. The code I'm working on is as follows:

#!/usr/bin/perl

use warnings;
use LWP::UserAgent;
use LWP::Debug qw(+);

#$ENV{HTTPS_PROXY} = 'xx.xx.xx.xx:xx';
$ENV{HTTPS_CERT_FILE} = '/tmp/test.pem';

my $xml=qq|<?xml version="1.0"?>
...
...|;

my $ua = LWP::UserAgent->new;
$ua->proxy(https  => 'xx.xx.xx.xx:xx');
my $req = HTTP::Request->new(POST => 'https://secure.server.com/test');
$req->content_type('text/xml');
$req->content($xml);
my $resp = $ua->request($req);
print $resp->as_string;

If I use LWP to set the proxy I get the following:

LWP::UserAgent::new: ()
LWP::UserAgent::proxy: https xx.xx.xx.xx:xx
LWP::UserAgent::request: ()
LWP::UserAgent::send_request: POST https://secure.server.com/test
LWP::UserAgent::_need_proxy: Proxied to xx.xx.xx.xx:xx
LWP::UserAgent::request: Simple response: Not Implemented
501 Protocol scheme '' is not supported
Content-Type: text/plain
Client-Date: Sun, 23 Apr 2006 23:36:48 GMT
Client-Warning: Internal response

501 Protocol scheme '' is not supported

I'd appreciate advice on interpreting this response.

If I use Crypt::SSLeay to set the proxy I get error messages from the 
proxy saying that access is denied. I'm certain the proxy is set up to 
permit access to the secure server, so I don't understand this. Here's 
the response (I've removed the HTML)

LWP::UserAgent::new: ()
LWP::UserAgent::request: ()
LWP::UserAgent::send_request: POST https://secure.server.com/test
LWP::UserAgent::_need_proxy: Not proxied
LWP::Protocol::http::request: ()
LWP::UserAgent::request: Simple response: Internal Server Error

500 proxy connect failed: PROXY ERROR HEADER, could be non-SSL URL:
HTTP/1.0 403 Forbidden
Mime-Version: 1.0
Date: Mon, 24 Apr 2006 01:02:07 GMT
Content-Type: text/html
Content-Length: 1104
Expires: Mon, 24 Apr 2006 01:02:07 GMT
X-Squid-Error: ERR_ACCESS_DENIED 0
X-Cache: MISS from my.proxy.com
Proxy-Connection: close

ERROR
The requested URL could not be retrieved
While trying to retrieve the URL:
xx.xx.xx.xx:xx
The following error was encountered:
Access Denied.

Access control configuration prevents your request from
being allowed

==============================================

Without the proxy I get a peer certificate verification error.

Given my setup and requirements, is there any need to specify a 
certificate location? Shouldn't I be verifying the certificate sent by 
the server?

I am using perl 5.8.6, LWP 5.805, Crypt::SSLeay 0.51, and openssl 
0.9.7i. I'm running under Linux 2.4.26-1.2smp


Regards

Chris