Well, i using this with CakePHP and i got this NOTICE:
Notice (8): Undefined index: JPG Support [APP\vendors\phpThumb\GdThumb.inc.php, line 1080]
So for fix it i did:
case 'JPG':
$isCompatible = (isset($gdInfo['JPG Support'])) ? $gdInfo['JPG Support'] : $gdInfo['JPEG Support'];
break;
case 'PNG':
$isCompatible = $gdInfo['PNG Support'];
break;
The problem was that gdInfo dont had JPG Support index.
I wish that it help...