All I meant was that all three of those technologies are famous for their unreliability. OK perhaps the flash runtime not so much, it's disliked for different reasons. It's definitely true of the other two. I've had to talk soap to a coldfusion service before and it's not an environment conducive to safe programming.
All it takes is one piece of code in the chain deciding to "helpfully" "fix" cases where people have stringified null values in a system that stringifies null to "null" by "translating them back" to null, and voila, you have a broken system.
A lot of problems like these are down to programmers that try to fix bugs by fixing the symptoms.
For example:
<elem>Null</elem> - element equal to "Null"
<elem/> - empty element (can also have a nil attribute set to true).