If you sleeping is disturbing your job performance, then ... screw that job!
To be trully productive my work must not be tied to specific time-slice. Sometimes I am most productive 9-17, sometimes 16-24, sometimes 0-8.
On the other hand today I started to try to rise early following Steve Pavlina. Yay to me! Let's hope I can keep rising at 5 in the morning for at least a week, so I can truly evaluate the result.