I didn't realize that. Did Obama actually send it back to the House?
Given that both houses essentially approved of this unanimously, I don't see how a veto matters.
I've been wondering if that's what this is all about: since it was passed on a voice vote with no objections in the House and unanimous consent in the Senate, then Obama is afraid that a regular veto would be overridden.
When Bush tried this in 2007, Pelosi said that they would treat it as a veto that could be overridden. But the House ultimately passed a nearly identical bill that addresses Bush's objections.
He can’t send it back to the house, because the house is not in session — there is nobody there to send it back to. Hence, the “pocket veto”.
I could see a paragraph added to the bill that would alleviate the concerns raised by posters here, without messing up the bill. But I’m certain the white house wants something much more dark and ominous.