Yeah, mapquest doesn't yet have this address in its database. But as I live there, I can vouch that it does in fact exist. Mapquest does suggest similar addresses, and those directions work too.
As you go down Arroyo drive, you will see a driveway with a sign on the left that says Vista Del Campo Norte. Turn in there. The venue will be the first building on your right as you enter the driveway. Note that the room is on the SECOND floor of the building.
The place does have rules against gambling, but I don't think a tournament can be considered gambling so I think we're alright there. However, I would appreciate it if you guys kept the money thing on the down low. So if it's alright with Claire, I would suggest maybe you guys pay when you arrive and we'll just right your name down on a registration paper so we can avoid a big line of people paying money? Like I said, I'm sure we'll be fine regardless, it's just a suggestion though.