Description:
------------
I've been running into a problem where a single character string will turn into a '?' character when I attempt to concatenate it or interpolate it with a single "\n" character.

If I use a multi-character string or multiple "\n" characters I don't get '?' characters anymore.

I'm running this from the console.

Reproduce code:
---------------
<?php

class Environment {
//todo:  add persistance

	const ALLPAIRS = 0;
	const EXHAUSTIVE = 1;

	///factors is a multidimenstional associative array.
	///the key for the main array is the factor.  The value of that key is a traditional array of values
	private $factors;
	
	///FactorMaps are 1:1 concrete representations made out of the factors
	private $factorMaps;
	
	///Mode states how FactorMaps are made from the factors
	///Currently, allpairs and exhaustive are supported
	private $mode;
	
	public function __construct($mode=Environment::ALLPAIRS) {
		$this->factors = array();
		$this->factorMaps = array();
		$this->mode = $mode;
	}
	
	public function addFactorValues($factor, $values) {
		if (!isset($this->factors[$factor])) {
			$this->factors[$factor] = array();
		}
		$this->factors[$factor] = array_merge($this->factors[$factor], $values);
		//todo:  update the factormaps if any factors were added
	}
	
	public function getFactorValues($factor) {
		return $this->factors[$factor];
	}
}

?>

/////////////////////////////////////////////

<?php
	require('../Environment.php');
	
	$enviro = new Environment();
	$enviro->addFactorValues('test', array('a', 'b', 'c', 'd'));
	foreach($enviro->getFactorValues('test') as $val) {
		echo("$val\n");
	}
	
?>

Expected result:
----------------
a
b
c
d

Actual result:
--------------
????