Indeed I have no sleep schedule at all, but I doubt it's related to Nexuiz, it's just the same when I'm not playing it for long periods of time. I have been like this since I was a kid, I can't figure out when it actually started, but I know I was like that in High School.
I stay up for over 24 hours 2 or 3 times a week, and it seems to be random. I think I'm just more comfortable living at night, but I need to be awake during the day sometimes for work related stuff or other RL stuff. Basically, if it's past 4am, the question is always "is it worth going to sleep or should I stay up since I have things to do in the morning?". Often, if I've been up over 24 hours, I STILL am not able to sleep during night, so I end up being up for 30+ hours quite often. It is a constant fight, sometimes I get so tired after a few days that I'll sleep for 16+ hours, usually on Saturdays because that's the day where I don't have much to do. So that's the one thing that seems consistent; I sleep a lot on Saturdays. I'll be 30 soon, I don't know if I can keep that up, it's probably not that healthy

That and the booze, coffee and cigarettes. I've been told many times that I'll be lucky if I make it past 50 years old.