Eight Ball Question

I have not had this problem happen many times, only once that i recall. But when the break is made in a game of 8 ball and both the cue ball and eight are sunk on the break,what is the proper ruling by the books.Some people go by the house rules,but id rather have a justified answer.

[Elvis]

I play in 2 different leagues. In one league if you make the 8 on the break you win, but if you make the 8 and scratch you lose. In the other league if you make the 8 on the break you can chose to spot it and keep shooting or have the balls re-racked and break again. If you make the 8 and scratch your opponent has the choice of spotting the 8 and shooting or re-rack and break themselves. The first league I mentioned was VNEA but it gives both sets of rules in the rule book and the league picks which set they will go by..hope this helps somewhat