Health,
You appear to be mixing up two of the Supreme Court cases decided yesterday (not that this is the only problem with what you have written).
The DOMA case was about a federal law that defines marriage for all federal purposes as being between one man and one woman. The Court held this unconstitutional as a deprivation of the rights of those who want to marry someone of the same gender. This was a substantive ruling.
The Prop 8 cases was about the California referendum that outlawed same-gender marriage that was deemed unconsitutional by the District Court. The Supreme Court held that the party appealing the decision (people who organized to get Prop 8 passed) did not have standing to appeal because they were not personally injured by the District Court’s ruling. This was a procedural ruling.