Useful to know that if you pass a string into the construct and the class cannot be instantiated for some reason a SPL LogicException will be thrown.
This code was ran on a Mac OS X 10.6.7, AMP, PHP 5.3+
<?php
// index.php
try {
$ReflectedClass = new ReflectionClass('NonExist');
} catch (LogicException $logicDuh) {
print_r($logicDuh);
}
?>
Will return a deeply nested array full of useful information about the error.