If a class is overloaded and it uses __call() the 
overloaded class cannot return anything from its methods. 
Example code:

<?php
class Foo {

    var $bar = 'barvalue';

    function Foo() {
    }

    function getBar() {
       return($this->bar);
    }

    function printBar() {
       print($this->bar);
       return('foo');
    }

    function getAny() {
        return('Any');
    }

    function __call($method,$params,&$return) {
        $return=$method($params[0]);
        return(true);
    }
}

overload('Foo');

$f = new Foo();

print '$f->getBar(): ' . $f->getBar() . "\n";
print '$f->printBar(): '; print $f->printBar(); print "\n";
print '$f->bar: ' . $f->bar . "\n";
print '$f->getAny(): ' . $f->getAny() . "\n";
?>

output is:

$f->getBar(): 
$f->printBar(): barvalue
$f->bar: barvalue
$f->getAny(): 

after removing the function __call() from the class it 
works as expected. Output is then:

$f->getBar(): barvalue
$f->printBar(): barvaluefoo
$f->bar: barvalue
$f->getAny(): Any