(For those who are looking at this thread -- this is highly technical stuff: don't worry about it if you don't understand, as it doesn't have to do with SuperDuper!)
I don't think this has to do with the
Floating User stuff at all, actually.
There might be a special way to indicate this kind of user in Tiger. I'd check the other similar users in NetInfo, and see if there's a special property you need to assign.