(Command Line Example that works)
shell#curl -d 'level=2&pass=password&hsam_timeout=20' -k https://1.1.1.1/auth
AUTH: OK
SESSION: 4221231856

(EXAMPLE TEST with module distro t/new/06http-post.t)
$curl->setopt( CURLOPT_URL,           $ENV{CURL_TEST_URL} );
$curl->setopt( CURLOPT_READFUNCTION,  \&read_callback );
$curl->setopt( CURLOPT_INFILESIZE,    $max );
$curl->setopt( CURLOPT_UPLOAD,        1 );
$curl->setopt( CURLOPT_CUSTOMREQUEST, 'POST' );
my $code = $curl->perform;

(My code that also turns off the ssl check)
$curl->setopt( CURLOPT_URL,'https://1.1.1.1/auth?level=2&pass=password&hsam_timeout=20'            );
$curl->setopt( CURLOPT_READFUNCTION,  \&read_callback );
$curl->setopt( CURLOPT_INFILESIZE,    $max );
$curl->setopt( CURLOPT_UPLOAD,        1 );
$curl->setopt( CURLOPT_CUSTOMREQUEST, 'POST' );
$curl->setopt(CURLOPT_SSL_VERIFYPEER,0); 
$curl->setopt(CURLOPT_SSL_VERIFYHOST,0); 
my $code = $curl->perform;

##</code><code>##

$curl->setopt( CURLOPT_POST, 1);
$curl->setopt( CURLOPT_POSTFIELDSIZE, 100);
$curl->setopt( CURLOPT_POSTFIELDS, "level=2&pass=password&hsam_timeout=20");

##</code><code>##

> POST /auth?level=2&pass=password&hsam_timeout=20 HTTP/1.1
Host: 10.2.200.101
Accept: */*
Content-Length: 100
Expect: 100-continue

< HTTP/1.1 417 Expectation Failed
< Connection: close
< Content-Length: 0
< Date: Tue, 19 May 2009 02:16:25 GMT
< Server: httpd
< 
* Closing connection #0