I have a similiar problem as this, only that with a double bed. My theory is simple - sleeping gets * ater you move a Sim to a new family.
My sim was friends with one female sim for a while and I took her visiting one day in a flirty mood as a chance to start hitting on her, eventually my sim had the first kiss and woohoo with her and yadda yadda, then I invited her to move in and she agreed. Soon after she was added to the family she was hit with the no sleep bug - she's do to bed, sleep only for a short while and get up without recovering any energy - same thing with trying to take a nap. Obviously she ended up being fatigued and passing out while unable to actually sleep.
By chance I found a post talking about a similiar issue and they mentioned that editing the sim fixed it. So I started editing the girl sim's outfits via the dresser (which I'd do anyway since she was rather cute but had all that ruined by awful eye makeup) and voila - after editing the sim she was able to sleep just fine.
The suggestion here is for all posters to say if they got hit by this bug after adding a new sim to a family via move or something, and anyone experiencing this please edit the afflicted sims to check if it fixes it