Description:
------------
APC 3.0.8 doesn't work with __isset overloading (PHP 5.1.0, Apache 2.0.54)

Reproduce code:
---------------
<?php
class test {
    public function __isset($var) {
        return true;
    }
}

$test = new test;

if (isset($test->test)) echo ".";
// $test->__isset('test') works
?>

Expected result:
----------------
Shouldn't output anything

Actual result:
--------------
Apache error.log:
[notice] Parent: child process exited with status 3221225477 -- Restarting.