Originally posted by Gila Monster:
And if someone could translate it into english...
[Sal]What do I look like? A guy who's not lazy?[/Sal]
Basically it tells what has already been mentioned in other posts. The code xACVyy is related to the production of Futurama, not the airingschedule. X is the productionserie, yy is the episode in that production.
It goes on to explain that some episodes can be held over to the next season for various reasons. Also the airing-order can be somewhat different from the production-order, due to Valentines Day, Chrismas etc.