Having Problems using the PDFlib in PHP 5

[climbjm]

I have installed the PDFlib on my server.  When I run phpinfo() it says PHP 5.1.6, and in the 'configure command' section it states '--with-pdflib'.  When I run my script I get a:
[tt]
Fatal error: Class 'PDFlib' not found in /home/username/public_html/get_pdf.php on line 9.[/tt]

This is the code I am trying out:
[code]
<?php
try
{
$p = new PDFlib(); // this is line 9 in my script.

// open new PDF file; insert a file name to create the PDF on disk
if ($p->begin_document("", "") == 0) {
die("Error: " . $p->get_errmsg());
}

$p->set_info("Creator", "get_pdf.php");
$p->set_info("Author", "Just Me");
$p->set_info("Title", "Hello world (PHP)!");

$p->begin_page_ext(595, 842, "");

$font = $p->load_font("Helvetica-Bold", "winansi", "");

$p->setfont($font, 24.0);
$p->set_text_pos(50, 700);
$p->show("Hello world!");
$p->continue_text("(says PHP)");
$p->end_page_ext("");

$p->end_document("");

$buf = $p->get_buffer();
$len = strlen($buf);

header("Content-type: application/pdf");
header("Content-Length: $len");
header("Content-Disposition: inline; filename=hello.pdf");
print $buf;
}
catch (PDFlibException $e)
{
die("PDFlib exception occurred in hello sample:\n" .
"[" . $e->get_errnum() . "] " . $e->get_apiname() . ": " .
$e->get_errmsg() . "\n");
}
catch (Exception $e)
{
die($e);
}
$p = 0;
?> [/code]

Any thoughts or ideas anyone?