I've seen issues with Drupal's compatibility with PHP Version 5.3.1, and Admin Module doesn't need to go ignored, it's a great module for site management. The attached file fixes the issue for PHP 5.3.1, hope it helps anyone who uses it.
I don't know where to contribute module patches or what-not. This is actually a first for me, so hope people find it. Maybe the maintainers can apply this to the main download. This is the full module. I don't think update.php is necessary when applying it. Just to be safe, use it at your own risk! :)