Fatal error: Cannot redefine class constant PelTag::XP_COMMENT

When installed on Drupal 5 RC1 with image.module v 1.208 and PEL .9, I get this error on both an XAMPP install on XP and an Entrophy install on OSX. I'm using PHP 5.1.6 on XAMPP and and 5.1.5 on OSX.

Fatal error: Cannot redefine class constant PelTag::XP_COMMENT in C:\Program Files\xampp\htdocs\drupal5\modules\exif\pel\PelTag.php on line 1086