I have personally encountered "Null" as a surname in system used by job applicants world-wide. The system's session layer encodes absent values as the string "null" at some point. The Null clan is the only problematic case, and they are numerous enough that the maintainers are aware of the problem but not so numerous to fix the session layer.

I wish I could listen in on a dinner conversation at Null house. They must have an interesting perspective about computers.

'The string "Null" should not cause this behavior.'

FTFY. It's certainly possible there's a bug in the library.

The OP claims it's real. After dealing with some SOAP systems I would entirely believe this is possible.

I know someone named Null who's had similar problems as a user of web apps. In fact I mentioned it here a while back: http://news.ycombinator.com/item?id=1440890

It could very easily be real. I was in a Fantasy Football league on Yahoo a few years ago, and there was a player named Keith Null who played briefly after another player was injured. His name just showed up as Keith.