I have a simple script.

<?php
$a = "hello"."\n"."Dave"."\0"."I have added a null"."\0"."or 2"."\n";
echo $a;
var_dump($a);
echo "stop here";
?>

When I get the property for $a, the information I get back is

<?xml version="1.0" encoding="iso-8859-1"?>
<response command="context_get" transaction_id="168"><property name="a" fullname="$a" address="10208552" type="string" size="36" encoding="base64"><![CDATA[aGVsbG8KRGF2ZQ==]]></property></response>

So the size is correct, but the string information is only part of it and it returns only up to the first embedded null.