PHP/GD2: undefined function imagettftext()

Hello,

I have a PHP script that works perfectly on one server but causes a fatal error on another:

        Fatal error: Call to undefined function imagettftext() on line 8

Both have GD2 installed.  I use PHP 5.2.4.  Any ideas why this is not working?  Here is my script:


<?php

print_r (better_imagettfbbox ('12', '44', 'arial.ttf', 'Hello World'));

function better_imagettfbbox($size, $angle, $font, $text) {
  $dummy = imagecreate(1, 1);
  $black = imagecolorallocate($dummy, 0, 0, 0);
  $bbox = imagettftext($dummy, $size, $angle, 0, 0, $black, $font, $text);
  imagedestroy($dummy);
  return $bbox;
}
?>