I have a code base built for PHP 5.3, but due to circumstances (and morons) beyond my control I've been forced to backport it to PHP 5.2. There are some nasty surprises not documented in the normal places. __DIR__ define('APP_ROOT', dirname(__DIR__)); doesn't work because __DIR__ isn't defined in 5.2.
Maybe I don't understand xQuery enough yet. I've only been working with it for a little while, and it's a very strange, arcane language. But I don't understand why these two functions return different results. The text between the smiley parentheses should be a comment, ignored by the parser and not output. But it isn't ignored.