I'm thinking it's NOT GD. Here's why:

I was able to generate a sample graph using GD and php with the following code:

header("Content-type: image/png");
$arrval = array(12,123,21,32,77,85,166,176,163,121);
$height = 260;
$width = 330;
$im = imagecreate($width,$height);
$white = imagecolorallocate($im,255,255,255);
$gray = imagecolorallocate($im,200,200,200);
$black = imagecolorallocate($im,0,0,0);
$red = imagecolorallocate($im,255,0,0);
$x = 21;
$y = 11;
$num = 0;
while($x<=$width && $y<=$height){
$prcnt = ((($height-50)-($y-1))/($height-60))*100;
imageline($im, 21, $y, $width-10, $y, $gray);
imageline($im, $x, 11, $x, $height-50, $gray);
imagestring($im,2,1,$y-10,$prcnt.'%',$red);
imagestring($im,2,$x-3,$height-40,$num,$red);
$x += 30;
$y += 20;
$num++;
}
$tx = 20;
$ty = 210;
foreach($arrval as $values){
$cx = $tx + 30;
$cy = 200-$values;
imageline($im,$tx,$ty,$cx,$cy,$red);
imagestring($im,5,$cx-3,$cy-13,'.',$red);
$ty = $cy;
$tx = $cx;
}
imageline($im, 20, 11, 20, $height-50, $black);
imageline($im, 20, $height-49, $width-10, $height-49, $black);
imagestring($im,3,10,$height-20,'Line Graph by: Roseindia Technologies
+',$red);
imagepng($im);
[download]

So that tells me GD is installed properly and working.

I'm still getting the same "font not found" error, so it's down to a perl problem.

You're the perl monks, right? Any wisdom?