I don't get these scheduling decisions, Davydenko/Robredo played a late evening match and Roddick a late match, while Djokovic had an early match and Almagro a w.o., and they schedule Djokovic for the evening session? Doesn't make any sense at all. The same was true in Barcelona and the common thing is tournament supervisor Carlos Sanches who apparently has little respect for player's resting times.
It's a puzzle, the tournament director has to care for many wishes.
1. Federer doesn't want a night match and they can't have him up first -> let's put him in the 2nd slot
2. Robredo played a night match today, he can't be put there again and he can't be first -> 3rd slot
3. Wawrinka-Blake and Djokovic-Almagro left, which is the more interesting night match for the public? -> Djokovic-Almagro (and Wawrinka played a night match on Monday)