you are not alone! I also have no trouble sleeping well, and yet I also sit up until the small hours, fiddling with the computer, procrastinating though I'm dead tired and longing for sleep. And I know I'm beeing an idiot, and that I really need the sleep I'm avoiding.
I can see two reasons:
One is that I get so tired that it's easier just to stay up than to wash and floss and brush - which is exhausting. So I wait, and wait, and wait......
The other is that I am beginning to realize what it means to be obsessively compulsive about something. The computer is beginning to draw me like a magnet.
I still love to read. I used to read in bed, but now I wake up when the book crashes down on my nose two minutes after I think I've begun to read.
And Paula, I also scream and moan in the night and frighten my poor husband, who thinks I'm in pain or having horrible nightmares, while I actually invariably have fun and entertaining dreams, but a dream laugh comes through sounding like a moan.

ZZZZZZZZ
birte